Clemco GritWizard Quick start guide

GritWizard™
PNEUMATICALLY OPERATED
ABRASIVE METERING VALVE
O. M. 31199
DATE OF ISSUE: 08/22
REVISION:
© 2022 CLEMCO INDUSTRIES CORP.
One Cable Car Dr.
Washington, MO 63090
Phone [phone]
Fax [phone]
Email: [e-mail]
www.clemcoindustries.com
Do not use this equipment
before READING this
MANUAL and
UNDERSTANDING its
contents.
These WARNINGS are
included for the health
and safety of the operator
and those in the
immediate vicinity. Failure
to read and understand
these warnings can result
in injury or death.
Electronic files include a
preface containing the
same important
information as in the
orange cover.
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PREFACE
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[I]
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• Employers are responsible for identifying all job site hazards, educating and training all persons who will operate and
maintain these products, and ensuring that all blast operators and their assistants understand the warnings and
information contained in these instructions relating to safe and proper operation and maintenance of this equipment.
• Serious injury or death can result from failure to comply with all Occupational Safety and Health Administration
(OSHA)regulations and all manufacturer’s instructions.
• This equipment is not intended for use in any area considered hazardous per National Electric Code NFPA 70 2011,
Article 500.
• Read this document and follow all instructions before using this equipment.


OSHA regulations relating to abrasive blasting are contained in the Code of Federal Regulations, Title 29 (29 CFR 1910 General Industry;
1915 Maritime; 1926 Construction). The most pertinent include: 1910.94 Ventilation, 1910.95 Occupational Noise Exposure, 1910.132
Personal Protective Equipment, 1910.133 Eye and Face Protection, 1910.134 Respiratory Protection, 1910.135 Head Protection,
1910.244 (b) Remote Controls. Consult www.osha.gov for complete information.

NO T I C E TO PURCHASERS AND U SE R S OF OUR
P R ODU C T S AND T H I S I N F O R M A T I ON A L M A T E R I A L
Clemco proudly provides products for the abrasive blast
industry and is confident that industry professionals will use
their knowledge and expertise for the safe and efficient use of
these products.
The products described in this material, and the information
relating to these products, are intended for knowledgeable,
experienced users.
No representation is intended or made as to: the suitability of
the products described here for any purpose or application, or
to the efficiency, production rate, or useful life of these
products. All estimates regarding production rates or finishes
are the responsibility of the user and must be derived solely
from the user’s experience and expertise, not from information
contained in this material.
It is possible that the products described in this material may
be combined with other products by the user for purposes
determined solely by the user. No representations are
intended or made as to the suitability of or engineering
balance of or compliance with regulations or standard practice
of any such combination of products or components the user
may employ.
Abrasive blast equipment is only one component of an
abrasive blasting job. Other products, such as air
compressors, air filters and receivers, abrasives, scaffolding,
hydraulic work platforms or booms, equipment for lighting,
painting, ventilating, dehumidifying, parts handling, or
specialized respirators or other equipment, even if offered by
Clemco, may have been manufactured or supplied by others.
The information Clemco provides is intended to support the
products Clemco manufactures. Users must contact each
manufacturer and supplier of products used in the blast job for
warnings, information, training, and instruction relating to the
proper and safe use of their equipment.
GENERAL INSTRUCTIONS
This material describes some, but not all, of the major
requirements for safe and productive use of blast machines,
remote controls, respirator systems, and related accessories.
All equipment and accessories must be installed, tested,
operated and maintained only by trained, knowledgeable,
experienced users.
The blast operator and all workers in the vicinity must be
properly protected from all job site hazards including those
hazards generated by blasting.
Work environments involving abrasive blasting present
numerous hazards. Hazards relate to the blast process from
many sources that include, but are not limited to, dust
generated by blasting or from material present on the surface
being blasted. The hazards from toxic materials may include,
but are not limited to, silica, cyanide, arsenic, or other toxins
in the abrasives or in the coatings, such as lead or heavy
metals. Other hazards from toxins include, but are not limited
to, fumes from coating application, carbon monoxide from
engine exhaust, contaminated water, chemicals or asbestos.
In addition, physical hazards that may be present include, but
are not limited to, uneven work surfaces, poor visibility,
excessive noise, and electricity. Employers must identify all
job site hazards and protect workers in accordance with
OSHA regulations.
Never modify Clemco equipment or components or
substitute parts from other manufacturers for any Clemco
components or parts. Any unauthorized modification or
substitution of supplied-air respirator parts violates OSHA
regulations and voids the NIOSH approval.
IMPORTANT
Contact Clemco for free booklets:
Blast Off 2 – Guide to Safe, Productive, and Efficient Abrasive
Blasting, and Abrasive Blasting Safety Practices – Guide to Safe
Abrasive Blasting.
Clemco Industries Corp. One Cable Car Drive Washington MO 63090
Tel: [phone] — Fax: [phone]
Email: [email protected]
Website: www.clemcoindustries.com

PREFACE
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[II]
OPERATIONAL INSTRUCTIONS
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OPERATOR SAFETY EQUIPMENT
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OSHA regulation 1910.134 requires appropriate respiratory protection for blast operators and workers in
the vicinity of blasting. These workers must wear properly-fitted, properly-maintained, NIOSH-approved,
respiratory protection that is suitable for the job site hazards. Blast respirators are to be worn only in
atmospheres not immediately dangerous to life or health from which wearers can escape without use of
the respirator.

The employer must develop and implement a written respiratory protection program with required
worksite- specific procedures and elements for required respirator use. The employer must provide
effective training to employees who are required to use respirators. The training must be comprehensive,
understandable, and recur annually, and more often if necessary.

NEVER use abrasives containing more than one percent crystalline silica. Fatal diseases, such as silicosis,
asbestosis, lead or other poisoning, can result from inhalation of toxic dusts, which include, but are not
limited to, crystalline silica, asbestos, and lead paint. Refer to NIOSH Alert 92-102; and OSHA CPL 03-00-007:
“National Emphasis Program – Crystalline Silica”, in which OSHA describes policies and procedures for
implementing a national emphasis program to identify and reduce or eliminate health hazards from exposure
to crystalline silica. Numerous topics associated with the hazards of crystalline silica in silica blasting sand
can be found on http:// osha.gov/. Clemco urges users of silica blasting sand to visit this website, and read
and heed the information it contains.

Always make sure the breathing air supply (respirator hose) is not connected to plant lines that supply
gases that include, but are not limited to, oxygen, nitrogen, acetylene, or other non-breathable gas. Never
modify or change respirator air line connections without first testing the content of the line for safe
breathing air. Failure to test the line may result in death to the respirator user.

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• Breathing air quality must be at least GradeD,
as defined by the Compressed Gas Association
specification G-7.1, per OSHA Regulation 29 CFR
1910.134. When compressed air is the breathingair
source, a Clemco CPF (suitable sorbent bed filter)
should be used. Respirator hose connecting the
respirator to the filter must be NIOSH approved.
Non- approvedhose can cause illness from
chemicals employed to manufacture the hose.
• All workers must always wear NIOSH-approved
respirators when any dust is present. Exposure to
dust can occur when handling or loading abrasive,
blasting, cleaning up abrasive, or working in the
vicinity of blasting. Before removing the respirator,
test the air with a monitoring device to ensure it is
safe to breathe.
• Clemco respirators DO NOT removeor protect against
carbon monoxide or any other toxic gas. Monitoring
devices must be used in conjunction with the respirator to
ensure safe breathingair. Always locate compressors and
ambient air pumps where contaminatedair will not enter
the air intake.

• Always use Clemco lenses with Clemco respirators;
installing non-approvedlenses voids the NIOSH approval.
Respirator lenses aredesigned to protect the wearerfrom
rebounding abrasive; they do not protect against flying
objects, heavyhigh-speed materials, glare,liquids, or
radiation.
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INDUSTRY ORGANIZATIONS

For additional information, consult:
Occupational Safety and Health Administration (OSHA) - www.osha.gov
Compressed Gas Association (CGA) - www.cganet.com
TheSociety for Protective Coatings (SSPC) - www.sspc.org
National Association of Corrosion Engineers (NACE) - www.nace.org
American Society for Testing and Materials (ASTM) - www.astm.org
National Institute of Occupational Safety and Health (NIOSH) - www.niosh.gov
American National Standards Institute (ANSI) - www.ansi.org

PREFACE
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[III]
BLAST MACHINES AND REMOTE CONTROLS
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OSHA regulation 1910.169 describes the necessity of pressure relief valves on compressed air equipment. Do not
operate blast machines with air compressors that are not equipped with properly functioning pressure relief valves.
OSHA regulation 1910.244(b) requires the use of remote controls on blast machines.
Serious injury or death can result from many sources, among them:
Involuntary activation of the remote controls. Never modify or substitute remote control parts; parts are not
compatible among different manufacturers. Welding hose is not suitable for remote control hose. Its ID and material
composition make it unsafe for remote control use.
Exceeding the maximum working pressure. Clemco blast machines are built to ASME-code and carry a ‘U’ or ‘UM’
stamp, and National Board/serial number. Every machine is marked with its maximum working pressure. Never
exceed the maximum working pressure limits of the blast machine.
Uncontrolled blast stream. High-velocity abrasive particles will inflict serious injury. Always point the blast nozzle
in the direction of the blast surface only. Keep unprotected workers out of the blast area.
Welding on the blast machine. Never weld on the blast machine; welding voids the National Board approval and
may affect the dimensional integrity of the vessel.
Moving the blast machine. Never manually move a blast machine containing abrasive, any machine containing
abrasive must be moved with appropriate mechanical lifting equipment.
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HOSES, COUPLINGS, AND NOZZLE HOLDERS
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The inside diameter (ID) of air hoses, fittings, and connections
should be at least four times larger than the nozzle orifice size. Blast
hose ID should be three to four times the size of the nozzle orifice.
Example: a #6 nozzle (3/8” diameter orifice) calls for 1-1/2” ID blast
hose and 1-1/2” ID or larger compressor hose. All hose runs should be
kept as short as possible and run in as straight a line as possible to
reduce pressure loss.
To install, squarely cut the end of the hose so that it fits snugly
against the coupling or hose end shoulder. Always use the screws
recommended by the manufacturer ensuring that they do not
penetrate the inner wall. Make sure the couplings tightly fit the hose.
Install cotter pins at every connection or use couplings with built-in
lock-springs to prevent disengagement. Install safety cables at all
connections to prevent whipping if hoses disengage or blow out.
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MAINTENANCE AND REPAIR
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Completelyreadand follow all service instructions and recommended maintenance intervals. Always shut off compressor and
depressurize blast machine beforeperforming any maintenance. At everyservice interval, clean all filters, screens, and alarm systems. If
spring-loaded abrasive valves areused, always cage spring beforedisassembly.
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WARRANTY

The following is in lieu of all warranties, express, implied or statutory, and in no event shall seller or its agents, successors, nominees or
assignees, or either, be liable for special or consequential damage arising out of a breach of warranty. This warranty does not apply to any damage or
defect resulting from negligent or improper assembly or use of any item by the buyer or its agent or from alteration or attempted repair by any person
other than an authorized agent of seller. All used, repaired, modified, or altered items are purchased “as is” and with all faults. In no event shall seller
be liable for consequential or incidental damages. The sole and exclusive remedy of buyer for breach of warranty by seller shall be repair or
replacement of defective parts or, at seller’s option, refund of purchase price, as set forth below
:
1. Seller makes no warranty with respect to products used other than
in accordance hereunder.
2. On products seller manufactures, seller warrants that all products areto
be freefrom defects in workmanship and materials for a
period of one yearfrom dateof shipment to buyer, but no warranty is
madethat the products arefit for a particular purpose.
3. On products which seller buys and resells pursuant to this order, seller
warrants that the products shall carry the then standard warranties of the
manufacturers thereof,a copy of which shall be madeavailable to the
customer upon request.
4. Theuse of any sample or model in connection with this order is for
illustrative purposes only and is not to be construed as a warranty that the
product will conform to the sample or model.
5. Seller makes no warranty that the products aredelivered freeof the
rightful claim of any third party by way of patentinfringement or the like.
6. This warranty is conditioned upon seller’s receipt within ten (10)
days afterbuyer’s discovery of a defect,of a written notice stating in
what specific material respects the product failed to meetthis
warranty. If such notice is timely given, seller will, at its option, either
modify the product or part to correct the defect,replacethe product or
part with complying products or parts, or refund the amount paid for
the defectiveproduct, any one of which will constitute the sole liability
of the seller and a full settlement of all claims. No allowance will be
madefor alterations or repairs made by other than those authorized
by seller without prior written consent of seller. Buyershall afford
seller prompt and reasonable opportunity to inspect the products for
which any claim is madeas abovestated.
Except as expressly set forth above,all warranties, express, implied
or statutory, including implied warranty of merchantability, are
herebydisclaimed.

PREFACE
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[IV]
DAILYSET‐UPCHECKLIST
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Make sure all blast operators are properly trained and suitably attired with a blast suit, safety boots, leather gloves, respiratory and hearing protection. Every day before start up,
check all equipment components, including piping, fittings, and hoses, and valves, for leaks, tightness, and wear. Repair or replace as needed. Use the following checklist.

1. PROPERLY-MAINTAINED AIR COMPRESSOR sized to provide
sufficient volume (cfm) at given pressure for nozzle and other tools. ADD 50%
volume (cfm) reserve to allow for nozzle wear. Use large compressor outlet and
air hose (at least 4 times the nozzle orifice diameter). For oil-lubricated
compressors, the employer shall use a high- temperature or carbon monoxide
alarm, or both, to monitor carbon monoxide levels. If only high-temperature
alarms are used, the air supply shall be monitored at intervals sufficient to
prevent carbon monoxide in the breathing air from exceeding 10 ppm. Follow
the manufacturer’s checklist and maintenance instructions.
2. BREATHING-AIR COMPRESSOR (or oil-less ambient air pump)
capable of providing Grade D quality air, located in a dust free area. Read # 1
above.
3. CLEAN, PROPERLY-MAINTAINED NIOSH-APPROVED SUPPLIED-AIR
RESPIRATOR
worn by blast operators, and other workers exposed to blast dust.
Make sure all respirator components are in place — all lenses, inner collar, and
cape. Thoroughly inspect all components for wear. The NIOSH approval (approval
number is listed in the owner’s manual) is for a complete assembly from point of
attachment on the CPF (sorbent bed) filter to the complete respirator. Substitution of
any part voids the NIOSH approval.
4. CARBON MONOXIDE MONITOR/ALARM installed at the CPF filter or
inside the supplied-air respirator for monitoring for the presence of deadly CO gas
and warning the operator(s) when the CO level reaches an unacceptable level.
When an ambient air pump is used for breathing air, a CO monitor provides a
measure of safety. Read # 1 above.
5. BREATHING-AIR FILTER (OSHA-REQUIRED sorbent bed filter) for
removal of moisture and particulate matter in the compressed air breathing-air
supply. Monitor the condition of the cartridge and replace when odor is detected or
at 3 month intervals, whichever comes sooner. The breathing air filter does NOT
detect or remove carbon monoxide (CO). Always install a CO monitor/alarm.
6. BLAST MACHINE (bearing U or UM stamp, National Board Number, and
Maximum Working Pressure) sized to hold a 30-minute abrasive supply. Examine
pop-up valve for alignment. Check piping, fittings, screens, valves for tightness,
leaks, and wear. Always ground the machine to eliminate hazard of static shock.
Install a blast machine screen to keep out foreign objects. Use a blast machine
cover if left outdoors overnight. Never exceed the maximum working pressure of the
vessel.
7. AIR LINE FILTER (moisture separator) installed as close as possible to the
blast machine inlet and sized to match the size of the inlet piping or larger air supply
line. Clean filter and drain often. Damp abrasive causes operational problems.

8. REMOTE CONTROLS are required by OSHA and must be in perfect
operating condition. Test and check all components to ensure all parts are present
and fully functional. Use genuine replacement parts. NEVER mix parts from different
manufacturers. Never use welding hose for remote control hose.

9. BLAST HOSE should have an inside diameter sized to suit the blast nozzle.
The ID should be three to four times the size of the nozzle orifice diameter. Blast hose
should be arranged in as straight a line as possible from the blast machine to the
work area, avoiding sharp bends.

10. COUPLINGS AND NOZZLE HOLDERS should fit snugly on the hose and
be installed with manufacturer recommended screws. Coupling lugs must snap firmly
into locking position. Gasket must always be used to form a positive seal, and cotter
pins must be installed. Replace gasket when wear, softness or distortion is detected.
Check nozzle holder for thread wear; replace at any sign of wear. Install safety cables
at all connections.

11. NOZZLE orifice size should be checked and nozzle replaced when worn
1/16” from original size. (No. 5 nozzle has 5/16” orifice diameter; replace when it
measures 3/8”). Threads should be inspected daily for wear and nozzle should be
replaced when wear is detected. Always use a nozzle washer.
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12. ABRASIVE must be a material specifically manufactured for blasting. It
should be properly sized for the job. Check material safety data sheet for free-
silica, cyanide, arsenic, lead and other toxins and avoid use when these toxic,
harmful substances are present.
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SURFACE TO BE BLASTED should be examined for hazardous substances.
Take appropriate protective measures as required by OSHA to ensure the blast
operator, other workers in the vicinity, and any bystanders are properly protected.
©Clemco Industries Corp., Stock No. 20954P, 0692 Rev. F, 06/12
1. Air Com
p
resso
r
7. Air Line
Moisture
Se
p
arato
r
5. CPF Air Filte
r
6. ASME Code
Bl
as
t M
ac
hin
e
8. Remote
Co
ntr
o
l
s
9. Blast Hose 10. Hose Couplings and Safety Cables
11. Appropriately Sized Nozzle
12. Abrasive
4. External or
Helmet Mounted
Carbon Monoxide
Monitor /Alarm
2. Breathing Air Compressor for
High Pressure Respirators3. NIOSH Approved
Supplied-Air Respirator
or Ambient Air Pump for
Low Pressure Respirators

GRITWIZARD PNEUMATICALLY OPERATED Page 1
ABRASIVE METERING VALVE
© 2022 CLEMCO INDUSTRIES CORP.  www.clemcoindustries.com  Manual No. 31199
1.0 INTRODUCTION
1.1 Scope of Manual
1.1.1 These instructions cover the setup, operation,
maintenance, and replacement parts for Clemco’s
GritWizard™ (GW) Pneumatically Operated Abrasive
Metering Valves.
1.1.2 This manual contains important safety
information. All operators and personnel involved with the
abrasive blasting process must read and understand the
contents of these instructions, including the orange cover. It is
equally important that the operator is trained and qualified
to safely operate the blast machine, remote controls,
and all other equipment used with the blast machine.
1.1.3 All personnel involved with the abrasive blasting
process must be made aware of the hazards associated
with abrasive blasting. The Clemco booklet Abrasive
Blasting Safety Practices is included with every blast
machine; the booklet contains important safety
information about abrasive blasting that may not be
included in equipment operations manuals. To request
additional copies, email [e-mail].
1.2 Safety Alerts
1.2.1 Clemco uses safety-alert signal words, based on
ANSI Z535.4-2011, to alert the user of a potentially
hazardous situation that may be encountered while
operating this equipment. ANSI's definitions of the signal
words are as follows:
This is the safety alert symbol. It is
used to alert you to potential physical
injury hazards. Obey all safety
messages that follow this symbol to
avoid possible injury or death.

Notice indicates information that is considered
important, but not hazard-related, if not
avoided, could result in property damage.


Caution indicates a hazardous situation that, if
not avoided, could result in minor or moderate
injury.


Warning indicates a hazardous situation that, if
not avoided, could result in death or serious
injury.

Danger indicates a hazardous situation that, if
not avoided, will result in death or serious
injury.
1.3 Table of Contents
SUBJECT LOCATION
INTRODUCTION ........................................................ 1.0
Scope of Manual ......................................................... 1.1
Safety Alerts ............................................................... 1.2
Table of Contents ....................................................... 1.3
Pressure Specifications .............................................. 1.4
Components and Operating Principles ......................... 1.5
Abrasives .................................................................... 1.6
INSTALLATION ......................................................... 2.0
Remove Existing Metering Valve from Blast Machine ... 2.1
Install GT Metering Valve onto Blast Machine ........... 2.2
Connect Piping to the Metering Valve ........................ 2.3
Connect Control Hoses ............................................... 2.4
Test for Leaks and Operation ..................................... 2.5
ADJUST ABRASIVE FLOW ...................................... 3.0
SERVICE MAINTENANCE ........................................ 4.0
Servicing Notes ........................................................... 4.1
Disassemble Valve Sections ...................................... 4.2
Spring Chamber and Knob Assembly .......................... 4.3
Spool Housing Assembly ............................................ 4.4
4-Way Pilot Valve Assembly ....................................... 4.5
Main Housing Assembly ............................................. 4.6
Reassemble Valve Sections ....................................... 4.7
Reconnect Piping and Conrtrol Lines ......................... 4.8
Cutting Control Hoses and Reusing Hose Fittings ..... 4.9
Using Tube-Lock Fittings .......................................... 4.10
Troubleshooting ....................................................... 5.0
Air only – No Abrasive Flow ........................................ 5.1
Heavy Abrasive Flow .................................................. 5.2
Irregular Abrasive Flow ............................................... 5.3
Abrasive or Air Flow Continues After Releasing
the Control handle .................................................... 5.4
Abrasive Flow Continues After the Optional ACS
is Switched OFF ....................................................... 5.5
Abrasive Flow Decreases Shortly After Blasting Starts .. 5.6
Turning the Metering Knob Does Not Change
Abrasive Flow ............................................................. 5.7
Check Operation and Function of 4-Way Pilot Valve ... 5.8
Abrasive Bridging from Moisture ................................. 5.9

GRITWIZARD PNEUMATICALLY OPERATED Page 2
ABRASIVE METERING VALVE
© 2022 CLEMCO INDUSTRIES CORP.  www.clemcoindustries.com  Manual No. 31199
REPLACEMENT PARTS ........................................... 6.0
Replacement GritWizard Abrasive Metering Valves ..... 6.1
GritWizard Abrasive Metering Valve ........................... 6.2
1.4 Pressure Specifications
 Pressure to fully open the valve .................... 80 psi
 Maximum working pressure ........................ 175 psi
1.5 Components and Operating Principles
1.5.1 Main components of the metering valve
assembly are shown in Figure 1 and include the metering
valve and a 1-1/2" nipple to connect the valve to the blast
machine. There are two valve options as noted below:
 Metering valve with a flanged (shutoff) ball valve.
 Metering valve without the flanged ball valve and
includes a flanged inlet nipple.
Retrofit valves (when the GritWizard Valve replaces
another type of valve) include hose, tubing, and fittings
to convert the control plumbing.
1.5.2 Operating Principles
The GritWizard is a normally closed, pneumatically
operated, abrasive metering valve. When the valve is
idle (the control handle is up), air assisted spring
pressure keeps the valve closed. When control air is
applied (the control handle is pressed), the air-assist
vents and control-air pressure overcomes the spring
pressure and opens the valve to a specific point set by
turning the metering knob. When the control handle is
released, control pressure vents and spring pressure
closes the valve, stopping abrasive flow.
1
5
3
1
5
3
Figure 1
Some items removed or rotated for clarity.
Air Connections from RLX.
Abrasive Metering Knob
Tube Fitting
1-1/4" or 1-1/2" (1-1/2" shown) Flanged Outlet Pipe
Blast hose and pusher line connection.
Ball Valve Handle
Shown in closed position.
Inlet Pipe
Flanged (shutoff) Ball Valve
Cleanout Cover
Safety Valve
Safety-Valve Exhaust Filter/Muffler
Abrasive Adjustment Indicator Label
1-1/2" NPT HD Nipple
Hose Fitting
1-1/2" NPT HD Nipple
4-Way Pilot Valve
Air-Assist Vent Valve
Air-Assist Exhaust Filter/Muffler
Abrasive Metering Valve with Inlet Pipe
Stock No. 31171
Abrasive Metering Valve with Flanged Ball Valve
Stock No. 31158 and 31172
1-1/4" Flanged Outlet Pipe
Blast hose and pusher line connection.
Tube Fitting – Air supply for air-assist closing

GRITWIZARD PNEUMATICALLY OPERATED Page 3
ABRASIVE METERING VALVE
© 2022 CLEMCO INDUSTRIES CORP.  www.clemcoindustries.com  Manual No. 31199
1.6 Abrasives


Abrasives and dust from blasting may contain
toxic materials (e.g., lead paint, silica) that are
hazardous to workers. Before blasting, obtain a
safety data sheet (SDS) for the blast abrasive
and identify all substances removed by the
blasting process:
• Silica sand (crystalline) can cause silicosis,
lung cancer, and breathing problems in
exposed workers.
• Slags can contain trace amounts of toxic
metals such as arsenic, beryllium, and
cadmium and have the potential to cause
lung disease.
NO DUST IS SAFE TO BREATH. DUST
PRODUCED FROM ANY ABRASIVE OR FROM
THE BLASTING PROCESS CAN CAUSE
SERIOUS LUNG DISEASE AND DEATH WHEN
INHALED. It is the employer’s responsibility to
train employees to identify hazardous
substances and to provide suitable policies,
procedures, monitoring, recordkeeping, and
personal protective equipment.

Use only abrasives specifically manufactured
for blasting that are compatible with the surface
being blasted. Abrasives produced for other
applications may be inconsistent in size and
shape and produce an unsatisfactory finish,
contain particles that can jam the abrasive
metering valve, or cause irregular wear.
1.6.1 Selection of blasting abrasive can play a
significant part in worker health risk, job productivity, and
maintenance of the blast machine. DO NOT USE
abrasives containing more than 1% crystalline (free)
silica. Obtain safety data sheets (SDS) for the blasting
abrasive prior to blasting, paying particular attention to
worker health risks and presence of any hazardous/toxic
substances.
1.6.2. Abrasive size: The GritWizard™ is designed
to be used with most common abrasives ranging in
sizes from 16-mesh to 220-mesh. However, the blast
machine or accessories may limit the size and type of
abrasive to something between the coarse and fine
limitations of the valve. The choice of abrasive size
depends on the desired profile, cleaning rate, nozzle
size, and availability of clean dry air. Generally, larger
and denser abrasive provide a deeper profile, while
smaller abrasives clean faster. Most abrasive blasting is
done with abrasive sizes between 16-and 80-mesh.
Abrasive for cabinet use is generally between 50-mesh
and 180-mesh. Coarse mesh sizes may be used if the
nozzle orifice is large enough to prevent multiple
particles to pass without jamming. Finer abrasive
requires clean dry air to prevent bridging in the blast
machine or metering valve.
1.6.3 Sand: Sand should never be used because of
the respiratory hazards associated with abrasive
containing free silica.
1.6.4 Slags: Slag abrasives are compatible with the
valve. Obtain a safety data sheets (SDS) to identify
hazardous substances.
1.6.5 Steel: Steel shot and steel grit may be used but
attention must be given to moisture in the compressed
air, the recovery process, and weight of the abrasive.
Steel abrasive rusts under humid conditions, especially
with day and night temperature changes, or when
compressed air supplied to the vessel is damp with
condensation. Steel abrasives weigh approximate 250 lbs
per cuft. Steel abrasives are normally used in blast rooms
with recovery systems and protected from the elements.
1.6.6 Silicon carbide, aluminum oxide, and garnet:
These are the most aggressive of the commonly used
abrasives. Although aggressive abrasives such as these
may be used, the service life of any equipment
components which come in contact with these abrasive
will be reduced. To avoid unscheduled downtime,
periodically inspect the metering valve, hoses, and
nozzles for abrasive wear. Use nozzles lined with boron
carbide with aggressive abrasives.
1.6.7 Glass bead and crushed glass: are compatible
with the GritWizard Metering Valve.
1.6.8 Lightweight Abrasive: Plastic media and
agricultural media are compatible with the GritWizard
Valve, but generally require a blast machine with 60
degree conical bottom for continuous, uninterrupted
media flow.

GRITWIZARD PNEUMATICALLY OPERATED Page 4
ABRASIVE METERING VALVE
© 2022 CLEMCO INDUSTRIES CORP.  www.clemcoindustries.com  Manual No. 31199
2.0 INSTALLATION
2.1 Remove Existing Metering Valve from Blast
Machine
2.1.1 Empty the blast machine of abrasive and
depressurize the machine.

Failure to observe the following before
performing any maintenance on the blast
machine could cause serious injury or death from
the sudden release of trapped compressed air:
 Depressurize the blast machine.
 Bleed the compressed-air supply line to the
blast machine.
 Lockout
(be certain the air supply is off and
that it cannot be started while work is in
process)
and tagout
(make sure the air
supply is clearly marked to prevent re-
starting while work is in process)
the
compressed-air supply.
2.1.2 Shut down the compressed-air source, lockout
and tagout the air supply, and drain the air-supply line.
2.1.3 Before removing the existing metering valve,
refer to Figure 2 to determine the ground clearance
required for each of the valve options. Besides the
height of the GritWizard Valve, an additional 1-3/4" is
needed to allow for the installation nipple and blast hose
coupling. Measure the distance from the bottom of the
blast machine to ground level to make sure the blast
machine has the clearance to accommodate the valve.
NOTE: A 1-1/2" x 1-1/4" bushing may be required on
the blast machine, depending on the vintage of the
machine. The bushing increases the clearance to
needed to install the valve.
2.1.4 Make a note of the connections on the existing
metering valve because connections shown in the
illustrations can differ based on remote control options.
Remove control hose(s). If the type of control
connections are different from those supplied with the
GritWizard Valve, save the connections and hoses from
the existing valve for reuse.
2.1.5 Remove all blast machine piping (pusher line
adaptors, and blast hose fittings) from the metering
valve. Save them as some will be reused.
2.1.6 Remove the existing metering valve from the
blast machine.
* Overall dimensions are approximate and vary depending on pipe fitting engagement
Figure 2
Couplings are shown for reference
Flanged Ball Valve
11-7/8"
11-1/8"
*13-5/8"
*12-7/8"
1-1/2" Installation Nipple
GritWizard with Flanged
(Shutoff) Ball Valve
GritWizard Without Shutoff Ball Valve
1-1/2" Installation Nipple
Flanged Inlet Nipple
Blast Mach
ine
Blast Machine
Outlet Pipe
Outlet Pipe

GRITWIZARD PNEUMATICALLY OPERATED Page 5
ABRASIVE METERING VALVE
© 2022 CLEMCO INDUSTRIES CORP.  www.clemcoindustries.com  Manual No. 31199
2.2 Install the GritWizard™ Valve onto the Blast
Machine – Figure 3
Installation Notes:
Tighten and align the valve by using a wrench on the
flanged inlet nipple or ball valve only, as shown in Figure
3. Avoid applying pressure on the valve body or outlet
pipe (lower flange) to tighten or align the valve. Doing so
could damage the upper or lower flanges.

Avoid tightening the valve to the blast machine
or aligning the valve by using a wrench or
applying leverage on any part of the valve at or
below the upper flange. Doing so could damage
the flanges.
To ensure airtight seals and make assembly easier,
apply pipe-thread sealant to all male pipe threads.
Additional fittings may be required to connect the valve
to some blast machines and piping configurations.
The GritWizard Valve is nondirectional; air flow can
enter through either end of the outlet pipe, and the pipe
can be rotated 90 degrees in either direction.
Note: The illustrations show the installation onto a
portable blast machine. Installation on a bulk blast
machine is slightly different but the process is the same.
2.2.1 The upper flange (inlet pipe or flanged ball
valve, depending on the option ordered), 1-1/2" NPT
close nipple, O-ring, and two flange bolts are packaged
separately in a plastic bag. The upper flange will be
installed onto the blast machine before attaching the
valve section.
2.2.2 Apply thread sealant to both ends of the 1-1/2"
NPT installation nipple and use the nipple to attach the
upper flange to the machine as, shown in Figure 3.
2.2.3 Use a pipe wrench or strap wrench to grip the
valve body or body of the inlet nipple to tighten it onto
the blast machine. Do not use a wrench on or below the
flanges, as noted in Figure 3. Doing so could damage
the flanges.
2.2.4 The valve body may be rotated 90 degrees in
either direction. Rotate the body to the inlet flange, as
needed to provide the best access to the metering knob,
and cleanout cover. Make sure the O-ring is in place
before bolting the body onto the inlet flange.
1
5
3
5
1
3
Figure 3
* Rotate the (upper) flanged nipple or valve as needed to align the knob to a convenient position.
** Rotate the (lower) flanged outlet pipe 90 degrees in either direction as need to align the pipe with the pusher line.
B
last M
a
chine
Place wrench and
tighten only on the
wrench flats.
Avoid using a wrench
on or below this flange.
7/16-NC Flange Bolt (2)
O-Ring
** Flanged Outlet Pipe
* Flanged Ball Valve
Valve Body Assembly
O-Ring
1/4-NC Flange Bolt (4)
1-1/2" Installation Nipple
Place wrench and
tighten only on th
e
large diameter of
the flanged nipple.
Blast M
a
chine
Avoid using a wrench
on or below this flange.
O-Ring
7/16-NC Flange Bolt (2)
** Flanged Outlet Pipe
1-1/2" Installation Nipple
* Flanged Inlet Nipple
O-Ring
1/4-NC Flange Bolt (4)
Valve Body Assembly
Some items removed or rotated for clarity.

GRITWIZARD PNEUMATICALLY OPERATED Page 6
ABRASIVE METERING VALVE
© 2022 CLEMCO INDUSTRIES CORP.  www.clemcoindustries.com  Manual No. 31199
2.2.5 The outlet pipe flange may be rotated 90 degrees
in either direction. Rotate the outlet pipe to the valve
body, as needed to provide the best alignment with the
pusher line and blast hose connection. Make sure the O-
ring is in place before reconnecting the outlet pipe to the
valve body.
2.3 Connect Piping to the Metering Valve ‒ Figure 4
2.3.1 Apply pipe thread sealant to the male threads of
a new 1-1/4" NPT nipple (1-1/2" NPT when using the
1-1/2" outlet pipe) and connect the blast hose coupling
to the outlet pipe, as shown in Figure 4.
2.3.3 Apply pipe thread sealant to the male threads of
the pusher line and connect the pusher line to the outlet
pipe, as shown. NOTE: The old pusher line may be too
long or too short to connect to the fittings without it
streatching or kinking. Some adjustment can be done by
lengthening or shorting the nipples between the side-piping
tee and choke valve. If the pusher line does not fit
correctly, a shorter or longer pusher line is required.
A pressure-hold control system (blasting stops but the he blast machine remains
under pressure when the when the control hadle is released) is shown for reference.
Users’ plumbing may differ, but connection are the same regardless of the controls.
Figure 4
User provided pipe nipple.
Connect blast-hose
connection coupling.
Connect male end of pusher line to the flanged outlet pipe.
cou
pl
ing
.
Pusher Line
Use shorter or longer pi
pe
nipples as needed at
these
locations, to avoid s
tretching or
kinking the flexible pusher line.

GRITWIZARD PNEUMATICALLY OPERATED Page 7
ABRASIVE METERING VALVE
© 2022 CLEMCO INDUSTRIES CORP.  www.clemcoindustries.com  Manual No. 31199
2.4 Connect Control Hoses ‒ Figure 5
2.4.1 The GritWizard Valve uses compressed air to
assist in closing the valve. A separate air line, upstream
of the inlet valve, is required to supply air to the 4-way
pilot valve, as shown in Figure 5.
 The upper illustration in Figure 5 shows connections
for a pressure-release remote control system.
 The lower illustration shows connections for a
pressure-hold remote control system.
2.4.2 Refer to Figure 5 and assemble a tee, that is no
smaller that the the inlet valve, and fittings, as shown.
The necessary fittings come with field-installed retrofit
kits. Clemco pressure-hold systems already include a
tee. Note that the illustrations in Figure 5 are typical and
shown for reference; connect control fittings and hose(s)
in the same manner as was used with the previous
metering valve, and as noted in Paragraph 2.1.4. If
necessary, use the old fittings from the valve the GW is
replacing.
Summary: The GW connections are adding fittings
and tubing to accommodate the air-assist feature.
2.5 Test for Leaks and Operation: Test the
machine and piping for air leaks and check the operation
of the machine before filling with abrasive.
Some items are rotated for clarity.
Figure 5
1/4" NPT Hex Nipple
Existing twinline control hose to and from the RLX Control Handle.
Existing inlet tee, bushing, and control hose.
1/4" NPT Tee
1/4" NPT x 1/4" Tube Fitting
1/4" Tubing to the tube fitting on top of 4-way pilot valve.
This is the air-supply line for the air-assist closing feature.
Blast Machine with Clemco Pressure-Hold Remote Controls
3/16" x 18" Hose from ACS switch to fitting on 4-way adaptor plate.
Bushing
Inlet Tee
1/4" NPT x 1/4" Tube Fitting
1/4" Tubing to the tube fitting on top of 4-way pilot valve.
This is the air-supply line for the air-assist closing feature.
Existing twinline control hose to and from the RLX Control Handle.
3/16" x 18" Hose - From ACS switch.
Blast Machine with Clemco Pressure-Release Remote Controls

GRITWIZARD PNEUMATICALLY OPERATED Page 8
ABRASIVE METERING VALVE
© 2022 CLEMCO INDUSTRIES CORP.  www.clemcoindustries.com  Manual No. 31199
3.0 ADJUST ABRASIVE FLOW ‒ Figure 6
3.1 Optimum abrasive flow depends on the type and
size of abrasive and blasting pressure, and can best be
determined by experience. Use as little abrasive as
possible while maintaining the maximum cleaning rate.
The air-abrasive mixture should be mainly air. As a rule,
the stream of abrasive coming out of the nozzle should
barely discolor the air when seen against a contrasting
background.
3.2 The valve is closed when the knob is fully
clockwise. Increase abrasive flow by turning the knob
counterclockwise and decrease abrasive flow by turning
the knob clockwise, as shown in Figure 6. Begin with the
knob set two turns from fully closed. Increase flow by
turning the knob no more than 1/4 turn counterclockwise.
Allow 10 to 15 seconds for the flow to stabilize before
readjusting. Continue adjusting as described until the
correct flow is attained.
3.3 The indicator label behind the knob shows how
far the metering valve is open. When the knob is turned
in or out it moves over the label, allowing the operator to
reset the valve to the same position when abrasive flow
is temporarily changed.
4 6
10
2 8
Figure 6
4.0 SERVICE MAINTENANCE

To avoid serious injury from the sudden release
of compressed air, observe the following before
performing any maintenance:
• Depressurize the blast machine.
• Turn OFF the compressed-air supply.
• Lockout and tagout the compressed-air
supply.
• Bleed the air-supply line to the blast machine.
4.1 Servicing Notes
 Valves with flanged ball valve: If the flanged
shutoff valve and main body housing do not need to
be replaced, the metering valve may be serviced
while on the machine by closing the flanged shutoff
valve and closing the choke valve, located on the
pusher line.
 Valves without flanged ball valve: Follow
instructions in the blast machine operations manual,
and empty abrasive from the machine before
servicing the valve.
 Remove the tubings and control hoses (mark them
to make sure they are reconnected correctly) from
the top of the 4-way pilot valve and the side of the
adaptor plate.
 Many of the fasteners are secured with removable
thread lock, such as Blue Loktite®. Using an impact
wrench with hex bit sockets and hex sockets makes
disassembly and assembly easier.
 If the valve has a flanged shutoff valve and the
shutoff does not require service, close the valve and
separate the metering valve housing by removing
the two 7/16-NC flange bolts securing the housing to
the ball valve.
4.2 Disassemble Valve Sections – Figure 7
4.2.1 Use a 3/8" wrench to remove the four thru-bolts
and separate the sections, as shown in Figure 7. The
spring will be loose when the spring chamber is removed
from the spool housing.
4.2.2 Once the four thru-bolts are removed, the valve
is separated into three distinct sections:
 Spring chamber and knob assembly.
 Spool housing with 4-way pilot valve assembly
 Main housing with flanged ball (shutoff) valve and
outlet pipe.
Label
Turn the metering knob
counterclockwise for more
abrasive.
Turn the knob clockwise
for less abrasive.
Adjustment-Position
Indicator Label

GRITWIZARD PNEUMATICALLY OPERATED Page 9
ABRASIVE METERING VALVE
© 2022 CLEMCO INDUSTRIES CORP.  www.clemcoindustries.com  Manual No. 31199
Service of the valve sections can be done in any order
and as needed.
5
3
1
Some items may be rotated.
Figure 7
4.3 Spring Chamber and Knob Assembly – Figure 8
4.3.1 Disassemble the spring chamber
1. Hold the metering knob and use a 1/8" hex bit
socket and impact wrench to remove the 3/4" long screw
and thrust bearing. Once the screw is removed, the
thrust bearing, spacer, and retainer will be loose and can
be removed.
Figure 8
2. Inspect the damper washer. It should be at the end
of the bore in the spring housing. Replace it if damaged.
3. If the metering knob turns freely and does not
require service there is no need to disassemble it. Skip
to Section 4.3.2 to reassemble the spring chamber.
4. If the metering knob does require service, use a
3/16" hex bit socket to remove the 5/8" long socket head
screw. Pull the adjusting screw to remove it from the
metering knob. Rocking the screw may be needed to
loosen it from the knob.
5. Inspect the adjusting screw and bushing and replace
either if worn or damaged.
4.3.2 Reassemble the spring chamber
1. Clean all parts that are to be reused and replace any
worn or damaged parts. Make sure all male and female
threads are clean and free of abrasive.
2. If the adjusting screw bushing was removed, apply a
drop of removable thread lock to the first few male end-
threads. Use an adjustable wrench to tighten the
bushing into the spring housing.
3. Insert the adjusting screw into the knob and use a
3/16" hex bit socket to tighten the 5/8" long socket head
screw.
4. Screw the adjusting screw into the adjusting screw
bushing.
5. Make sure the damper washer is in place; the
adjusting screw should pass through the center hole and
the washer should be at the end of the bore in the spring
housing.
6. Assemble the thrust bearing as shown in Figure 9.
Insert the small end of the spacer into the rotating side
of the bearing. The retainer is on the fixed housing-side
of the bearing and the recessed side faces toward the
socket head screw.
7. Insert the 1/4-20 x 3/4" socket head screw through
the bearing assembly, as shown.
8. Apply a small drop of removable thread lock to the
end threads of the screw and use a 1/8" hex bit socket
and impact wrench to tighten the screw into the
adjusting screw.
Spring Chamber and Knob Assembly
Spool Housing
with 4-Way Pilot Valve.
Spring will be loose.
Main Housing, sho
wn with
flanged shutoff valve.
Spring washers (3) will be loose.
1/4-20 x 5/8" Socket Head Screw
Adjusting Screw
Metering Knob
1/4-20 x 3/4" Lo-Pro Socket Head Screw
Adjusting Screw Bushing
Spring Housing
Damper Washer
Thrust Bearing Spacer
Thrust Bearing
Thrust Bearing Retainer

GRITWIZARD PNEUMATICALLY OPERATED Page 10
ABRASIVE METERING VALVE
© 2022 CLEMCO INDUSTRIES CORP.  www.clemcoindustries.com  Manual No. 31199
Figure 9
9. If no service is needed on the spool housing
assembly or main body assembly, the valve sections
may be reassembled, per Sections 4.4 and 4.6.
4.4 Spool Housing Assembly – Figure 10
4.4.1 Disassemble the spool housing assembly
Figure 10
1. To prevent the diaphragms and internal parts from
turning while removing the plunger, temporarily place the
four thru-bolts through the diaphragm and spool housing
mounting holes.
2. Hold the housing securely and turn the plunger
counterclockwise to remove it.
3. Remove the plunger, plunger spacer, both
diaphragms, and diaphragm washer from the housing.
4. Remove the spring guide, diaphragm, and spool
assembly from the other end of the housing.
5. Use a 3/16" hex bit socket and impact wrench to
remove the socket head screw from the spool.
4.4.2 Reassemble the spool housing assembly
1. Clean all parts that are to be reused and replace any
worn or damaged parts. Make sure all male and female
threads are clean and free of abrasive. Use new O-rings
and diaphragms.
2. Put a new O-ring into the spool groove.
3. Push the 1" socket head screw through the
recessed side of the spring guide and through the
spring-side diaphragm, as shown in Figure 10.
4. Apply a small drop of removable thread lock to the
end threads of the socket head screw and screw it into
the smaller hole (1/4-20 threaded hole) in the spool.
5. Use a 3/16" hex bit socket and impact wrench to
tighten the screw into the spool.
6. Apply a generous amount of multipurpose lubricant
to the O-ring and push the spool through the bore in the
spool housing.
7. Push the plunger stem through the plunger spacer.
The stem goes into the larger side of the spacer, and the
smaller diameter faces toward the diaphragms.
8. Push the plunger stem (with spacer) through two
plunger-side diaphragms.
9. Place the diaphragm washer over the plunger stem.
The washer is symmetrical, so it does not matter which
side faces toward the diaphragms.
10. Apply a drop of removable thread lock to the end
threads of the plunger shaft and loosely screw it into the
larger hole (1/2" threaded hole) in the spool.
11. Keep the holes in the diaphragms and spool housing
aligned by temporarily inserting the four thru-bolts
through the four holes.
12. Hold the housing securely and tighten the plunger by
turning it by hand as tight as you can get it.
Spool housing shown without 4-way pilot valve for clarity.
1/4-20 x 3/4" Lo-Pro Socket Head Screw
Thrust Bearing Spacer
Fixed Casing
Thrust Bearing Retainer
Rotating side
Thrust Bearing
S
afety V
alves
Diaphragm Washer
1/4-20 x 1" SS Socket Head Screw
Spring Guide
Diaphragm, Spring Side
Diaphragms, Plunger Side (2)
Spool O-Ring
Spool
Spool Housing
Plunger
Plunger Spacer

GRITWIZARD PNEUMATICALLY OPERATED Page 11
ABRASIVE METERING VALVE
© 2022 CLEMCO INDUSTRIES CORP.  www.clemcoindustries.com  Manual No. 31199
13. If the safety valves were removed from the housing,
apply thread sealant tape or other thread compound to
the male threads before reinstalling them.
14. If the 4-way pilot valve requires service, skip to
Section 4.5.
15. If no service is needed on the spring chamber, main
body assembly, or 4-way pilot valve, the valve sections
may be reassembled, per Section 4.7.
4.5 4-Way Pilot Valve Assembly – Figure 11
4.5.1 Disassemble 4-way pilot valve assembly
1. Use a 7/64" hex key to remove the two 2-1/4" socket
head screws and washers to separate the 4-way valve
from the adaptor plate.
2. Use a 7/64" hex key to remove the two 1" socket
head screws to separate the adaptor plate from the
spool housing.
3. If the 4-way valve is being replaced, remove the
mufflers (with bushing) and 3/8" NPT tube fitting for
reuse, or replace them as needed.
"
5
1
3
Figure 11
4.5.2 Reassemble 4-way pilot valve assembly
1. Clean all parts that are to be reused and replace any
worn or damaged parts. Make sure all male and female
threads are clean and free of abrasive. Use new O-rings
and adaptor-plate gasket.
2. Insert the two 1" long socket head screws through
their respective holes in the adaptor plate.
3. Hold the screws in place while aligning the adaptor
plate gasket and pushing it over the screws.
4. Place the adaptor plate and gasket on the spool
housing, making sure all the holes line up before
tightening the screws to secure it.
5. Place the two larger and smaller O-rings into their
respective grooves on the top of the adaptor plate.
6. Set the 4-way valve onto the adaptor plate and
secure it with the two 2-1/4" long socket head screws
and washers.
7. If any of the fittings were removed, apply thread
sealant tape or other thread compound to the male
threads before reinstalling them.
4.6 Main Housing Assembly – Figure 12
4.6.1 Disassemble main housing assembly
Note: If the GritWizard Valve has a flanged ball valve) the
housing may be serviced without removing abrasive
from the machine unless the ball valve needs to be
replaced. The following instructions cover the complete
disassembly and reassembly of all main body parts. If
service is not required in an area, skip to the next.
1. Remove the pusher line and the blast-hose coupling
pipe from the flanged outlet pipe.
2. Remove the main housing from the machine by
either one of the following methods:
1. Unscrew the flanged ball valve or inlet pipe (with
main housing attached) from the blast machine.
2. Separate the metering housing from the ball
valve/inlet pipe by removing the two 7/16" flange
bolts that secures it to the housing.
Note: If the ball valve or inlet pipe require service, they
(it) must be removed from the machine.
#6 x 2-1/4" SH Screw (2)
1
/8
"
NPT
Tube
Fitting
#6 SS Washer (2)
4-Way Pilot Valve
Adaptor Plate
#6 x 1" SH Screw (2)
O-Ring (2)
1/2" ID x 5/8" OD Nom.
O-Ring (2)
3/4" ID x 7/8" OD Nom.
Adaptor-Plate Gasket
Spool Housing (Ref.)
Muffler (2)
3/8" NPT Tube Fitting

GRITWIZARD PNEUMATICALLY OPERATED Page 12
ABRASIVE METERING VALVE
© 2022 CLEMCO INDUSTRIES CORP.  www.clemcoindustries.com  Manual No. 31199
Figure 12
3. Use a 2" socket to remove the valve seat from the
housing.
4. Remove the seat gasket from the valve seat.
5. Remove the flanged outlet pipe from the housing by
using a 3/8" wrench to remove the four flange bolts that
secure it to the bottom of the housing.
6. Remove the cleanout cover from the housing by
using a 3/8" wrench to remove the three flange bolts,
securing it to the housing.
7. Remove the two flange bolts, securing the housing
to the flanged ball valve/inlet pipe.
8. Remove the O-rings from the top of the housing,
cleanout cover, and outlet pipe.
4.6.2 Reassemble main housing assembly
1. Clean all parts that are to be reused and replace any
worn or damaged parts. Make sure all male and female
threads are clean and free of abrasive. Use new O-rings
and valve seat gasket.
NOTE: If the flanged ball valve or inlet pipe was removed
from the machine, using a new 1-1/2" NPT nipple and
reattaching it to the machine now will make it easier to
reattach the metering housing later.
2. Place a new valve seat gasket on the valve seat and
use a 2" socket to tighten the seat into the housing.
Torque the seat to 35 ft lb.
3. Place a new O-ring into the groove on the outlet pipe
flange and use four flange bolts to attach the pipe to the
bottom of the housing. Use a 3/8" wrench to tighten the
flange bolts.
4. Place a new O-ring into the groove at the top of the
housing and use two flange bolts to attach the housing
to the flanged ball valve or inlet pipe. Tighten the bolts
securely.
5. Place a new O-ring on the cleanout cover and use
three flange bolts to attach the cover to the housing. Use
a 3/8" wrench to tighten the flange bolts.
6. Make sure all fasteners are tight, as leaks will cause
the valve to malfunction.
Main Body Housing
1/4" x 1" Flange Bolt (7)
Outlet Pipe
Flanged (shutoff) Ball Valve
7/16" x 3/4" Flange Bolt (2)
Cleanout C
o
ver
O-Ring (3)
Valve Seat
Valve Seat Gasket
1/4 x 1" Flange Bolt (7)
Flanged Inlet Pipe
O-Ring (3) 1-15/16" ID x 2-1/8" OD Nom.

GRITWIZARD PNEUMATICALLY OPERATED Page 13
ABRASIVE METERING VALVE
© 2022 CLEMCO INDUSTRIES CORP.  www.clemcoindustries.com  Manual No. 31199
7. If no service is needed on the spring chamber, spool
housing assembly, or 4-way pilot valve, the valve
sections may be reassembled, per Section 4.7.
4.7 Reassemble Valve Sections – Figure 13
4.7.1 Make sure all fasteners and fittings are tight.
Leaks will cause the valve to malfunction. Make sure all
male and female threads are clean and free of abrasive.
4.7.2 Push the four 4" long thru-bolts through the
spring housing.
5
3
1
Figure 13
4.7.3 Place the three spring washers and spring into
the housing and while holding them in place, insert the
four thru-bolts through the spool housing and
diaphragms.
4.7.4 Align the thru-bolts with the mounting holes in
the main housing and screw the bolts in to secure all the
valve sections.
4.7.5 Tighten the thru-bolts with a 3/8" wrench.
4.8 Reconnect Piping and Control Tubing
4.8.1 Apply thread sealant compound to male NPT
pipe threads before reconnection the pusher line and
blast-hose coupling piping.
4.8.2 Reconnect the control tubing to the 4- way valve
and adaptor plate.
4.8.3 Test the valve for leaks and function before
returning it to service.
4.9 Cutting Control Hose and Reusing Control-
Hose Fittings ‒ Figure 14

Failure to observe the following procedure
before performing any maintenance can cause
injury from the sudden release of trapped
compressed air:
 Bleed all compressed air-supply lines.
 Lockout and tagout the compressed-air
supply.
NOTE: Control hoses may be shortened and cut to length
as follows:
4.9.1 Remove the hose end by placing the sleeve in
a vise or use a backup wrench on the sleeve to prevent
it from turning. Unscrew the insert by turning it
counterclockwise.
4.9.2 Turn the sleeve clockwise to remove it from the
hose.
4.9.3 Cut hose to the required length.
4.9.4 Turn the sleeve counterclockwise to install it
onto the hose. Do not over-tighten the sleeve, stop
tightening as soon as the hose bottoms against the
sleeves internal shoulder. Over-tightening will cause
the hose to curl inward and could cause blockage.
4.9.5 Push the end of the insert into the sleeve, and
turn it clockwise to tighten until the insert hex is against
the sleeve.
Figure 14
Install
Sleeve
Insert
Control Hose
Remove
Install
Remove
Spring Chamber and Knob Assembly
Spool Housing
with 4-Way
Valve
Spring
Main Housing Assembly
4" Thru-Bolts
Spring Washers (3)

GRITWIZARD PNEUMATICALLY OPERATED Page 14
ABRASIVE METERING VALVE
© 2022 CLEMCO INDUSTRIES CORP.  www.clemcoindustries.com  Manual No. 31199
4.10 Using Tube-Lock Fittings ‒ Figure 15

Failure to observe the following procedure
before performing any maintenance can cause
injury from the sudden release of trapped
compressed air:
 Bleed all compressed air-supply lines.
 Lockout and tagout the compressed-air
supply.
4.10.1 To remove the tubing from tube-lock fittings,
push the retaining collar toward the fitting, which
releases the tubing so it can be easily removed by
pulling it out. Do not force it, only a slight pull on the
tubing is required if the retaining collar is pushed in
correctly.
4.10.2 Reconnect the tubing by inserting it through the
collar until it seats. Tug on the tubing to make sure it is
tight.
Figure 15
5.0 TROUBLESHOOTING
NOTE: This section only identifies conditions and problems
in the blast machine and remote control system. For
service information, always refer to the appropriate section
of this manual and accessory equipment manuals before
servicing the equipment.

To avoid serious injury from the sudden release
of compressed air, observe the following when
troubleshooting the machine and remote
controls.
 Turn OFF the air supply, and lockout and
tagout the air supply.
 Drain the air-supply line.
 When checking if the controls requires air,
always enlist the aid of another person to
operate the control handle, hold the nozzle
securely, and point it in a safe direction.
 Never strap the remote control handle lever
down in the operating position.
5.1 Air Flow Only – No Abrasive Flow
5.1.1 Metering valve closed or needs to be adjusted.
Adjust abrasive flow, per Section 3.0.
5.1.2 Optional ACS switch is closed. Make sure the
ACS is in the ON position with the ACS toggle pointing
away from nozzle. Refer to the RLX Control Handle
operations manual.
5.1.3 Leak or blockage in the control hose or fittings
between the control handle and the GritWizard Metering
Valve. Make sure control air is reaching the side port
fitting on the 4-way pilot-valve adaptor plate. Refer to
Section 5.8.
5.1.4 Blast machine is empty. Check abrasive level.
5.1.5 Obstruction in metering valve. Clear as follows:

To avoid serious injury, depressurize the blast
machine, and lockout and tagout the
compressed-air supply before continuing.
Tu
be F
itting
Retaining/Releasing Collar
To remove the tubing: Push the
collar in to release the tubing.
Pull the tubing straight out to
remove it from the fitting.
To connect the tubing: Push the
tubing into the fitting until it seats.
Gently pull on the tubing to make
sure it is securely fastened.

GRITWIZARD PNEUMATICALLY OPERATED Page 15
ABRASIVE METERING VALVE
© 2022 CLEMCO INDUSTRIES CORP.  www.clemcoindustries.com  Manual No. 31199
Fully open the control valve. (It is fully open when the
metering knob is turned fully counterclockwise.) While
blasting, close the choke valve to force out small
obstructions or wet abrasive.
For larger obstructions, shut the machine down to
examine the abrasive valve. Remove the cleanout cover
from the main body and clear obstruction.
5.1.6 Check the operation of the 4-way pilot valve, per
Section 5.8.
5.1.7 The metering valve may require service. Refer to
Section 4.0 to service the valve.
5.1.8 Abrasive bridging in the blast machine. Refer to
the blast machine operations manual and inspect the
inside of the machine for foreign material.
5.2 Heavy Abrasive Flow
5.2.1 Make sure the choke valve is fully open (handle
in-line with the valve and piping.
5.2.2 Abrasive metering valve may be open too far.
Refer to Section 3.0 to adjust the metering valve.
5.2.3 Inspect the metering valve for wear. The
metering valve may require service. Refer to Section 4.0
to service the valve.
5.2.4 If the valve is used with a pressure-hold remote
control system, check the diaphragm in the ACE Air
Valve for damage.
5.3 Irregular Abrasive Flow
5.3.1 Check the abrasive metering valve and air-
control lines for air leaks. The abrasive valve is a
normally closed valve and requires air to open; any leak
or fluctuation in pressure can cause the valve to close or
partially close.
5.3.2 Damp abrasive. To clear minor blockage, close
and opening the choke valve several times, per Section
5.1.5. Refer to Section 5.9 for additional information on
moisture.
5.3.3 Check control line pressure. Pressure below 80
psi will cause the metering valve to begin to close.
Pressure fluctuations causes the metering valve to
partially close and reopen.
5.4 Abrasive or Air Flow Continues After
Releasing the Control Handle
5.4.1 Control air may not be fully exhausting from the
control handle. Refer to the control handle and remote
control systems operation manuals.
5.4.2 Control air may not be fully exhausting from the
metering valve. With the control lever UP, open the
metering valve’s safety valve (closest to the metering
knob). If air vents and abrasive flow stops, there may be
a blockage in the line between the side of the 4-way
adaptor plate and control handle.
5.4.3 Open the air-assist vent valve (farthest from the
abrasive metering knob) if air does not escape, check
operation of the 4-way valve, per Section 5.8.
5.4.4 If the valve is used with a pressure-hold remote
control system, inspect the metering valve plunger and
seat for wear. Refer to service instructions in Section 4.0.
5.5 Abrasive Flow Continues After the Optional
ACS Is Switched OFF
5.5.1 While blasting, turn the ACS switch OFF (toggle
pointing toward the nozzle). A short spurt of air should
exhaust from the muffler. If it does, the ACS is working. If
air does not exhaust, remove the muffler and try again. If
it now exhausts, the muffler is plugged and should be
replaces. If it still does not exhaust, check the ACS
control line for blockage.
5.5.2 Worn plunger or plunger seat, or an obstruction
between the plunger and seat. Service the valve as
needed, per Section 4.0.
5.6 Abrasive Flow Decreases Shortly After
Blasting Starts
5.6.1 Air leak in the blast machine causing pressure
imbalance:
 Check for leaks in the blast machine and around the
metering valve.
 Make sure the exhaust (outlet) valve is not leaking.
Once the RLX Control Handle is pressed, there
should be NO leaks anyplace on the blast machine,
valves, or control lines.
5.6.2 Abrasive bridging in the blast machine. This is
usually caused from using very fine abrasive, using
spent abrasive, or from moist air. Refer to Section 5.9 for
additional information on moisture.