Gast ROA Series Manual

70-5300 G481PL (Rev. G)
Product Use Criteria:
• Pump only clean, dry air.
• Operate at 32ºF - 104ºF (0ºC - 40ºC).
• Protect unit from dirt & moisture.
• Do not pump flammable or explosive gases or use in an atmosphere that contains such gases.
• Protect all surrounding items from exhaust air. This exhaust air can become very hot.
• Corrosive gases and particulate material will damage unit. Water vapor, oil-based contaminants
or other liquids must be filtered out.
• Consult your Gast Distributor/Representative before using at high altitudes.
• This pump is oil-less and requires NO lubrication.
ROA/RAA
ROCKING PISTON OIL-LESS PUMPS
Operation & Maintenance Manual
WARNING
PLEASE READTHIS MANUAL COMPLETELY BEFORE USING
THIS PRODUCT. SAVETHIS MANUAL FOR FUTURE REFERENCE
AND KEEP INTHEVICINITY OFTHE PRODUCT.
www.gastmfg.com
ISO 9001 & 14001 CERTIFIED

2
Correct installation is your responsibility.
Make sure you have the proper installation conditions
and that installation clearances do not block air flow.
Blocking air flow over the product in any way can
cause the product to overheat.
Mounting
This product can be installed in any orientation.
Mounting the product to a stable, rigid operating
surface and using shock mounts will reduce noise and
vibration.
Plumbing
Remove plugs from the IN and OUT ports. Connect
with pipe and fittings that are the same size or larger
than the product's threaded ports. Be sure to connect
the intake and exhaust plumbing to the correct inlet
and outlet ports. Ports will not support plumbing.
Accessories
The product's external intake and exhaust muffler will
provide adequate filtration in most applications. Check
filters periodically and replace when necessary.
Consult your Gast Distributor/Representative for
additional filter recommendations.
Install relief valves and gauges at inlet or outlet or
both, to monitor performance. Check valves may be
required to prevent back streaming through the pump.
Motor Control
It is your responsibility to contact a qualified
electrician and assure that the electrical installa-
tion is adequate and in conformance with all
national and local codes and ordinances. The
metal capacitor must be grounded.
Determine the correct overload setting required to
protect the motor (see motor starter manufacturer's
recommendations). Select fuses, motor protective
switches or thermal protective switches to provide
protection. Fuses act as short circuit protection for the
motor, not as protection against overload. Incoming
line fuses must be able to withstand the motor's
starting current. Motor starters with thermal magnetic
overload or circuit breakers protect motor from over-
load or reduced voltage conditions.
The wiring diagram supplied with the product provides
required electrical information. Check that power
source is correct to properly operate the dual-voltage
motors.
Electrical Connection
c
Disconnect electrical power at the circuit breaker
or fuse box before installing this product.
Install this product where it will not come into
contact with water or other liquids.
Install this product where it will be weather
protected.
Electrically ground this product.
Failure to follow these instructions can result in
death, fire or electrical shock.
WARNING
Electrical Shock Hazard
c
This product must be properly grounded.
Do not modify the plug provided. If it will not
fit the outlet, have the proper outlet installed
by a qualified electrician.
If repair or replacement of the cord or plug is
necessary, do not connect the grounding wire
to either flat blade terminal. The wire with
insulation that is green or green with yellow
stripes is the grounding wire.
Check the condition of the power supply wiring.
Do not permanently connect this product to
wiring that is not in good condition or is
inadequate for the requirements of this product.
Failure to follow these instructions can result in
death, fire or electrical shock.
WARNING
Electrical Shock Hazard
WARNING
DANGER
Your safety and the safety of others
is extremely important.
We have provided many important safety messages
in this manual and on your product. Always read
and obey all safety messages.
This is the safety alert symbol. This symbol
alerts you to hazards that can kill or hurt you and
others. The safety alert symbol and the words
“DANGER” and “WARNING” will precede all safety
messages. These words mean:
You will be killed or seriously injured if you don’t
follow instructions.
You can be killed or seriously injured if you don’t
follow instructions.
All safety messages will identify the hazard, tell you
how to reduce the chance of injury, and tell you
what can happen if the safety instructions are not
followed.
INSTALLATION

3
Model with a power supply cord:
This product must be grounded. For either 120-volt or
220/240-volt circuits connect power supply cord
grounding plug to a matching grounded outlet. Do not
use an adapter. (See above diagram.)
In the event of an electrical short circuit, grounding
reduces the risk of electric shock by providing an
escape wire for the electric current. This product may
be equipped with a power supply cord having a
grounding wire with an appropriate grounding plug.
The plug must be plugged into an outlet that is prop-
erly installed and grounded in accordance with all local
codes and ordinances.
Check with a qualified electrician or serviceman if
the grounding instructions are not completely
understood, or if you are not sure whether the
product is properly grounded. Do not modify the
plug provided. If it will not fit the outlet, have the
proper outlet installed by a qualified electrician.
Model that is permanently wired:
This product must be connected to a grounded,
metallic, permanent wiring system, or an equipment
grounding terminal or lead on the product.
Power supply wiring must conform to all required
safety codes and be installed by a qualified person.
Check that supply voltage agrees with that listed on
product.
Extension cords:
Use only a 3-wire extension cord that has a 3-blade
grounding plug. Connect extension cord plug to a
matching 3-slot receptacle. Do not use an adapter.
Make sure your extension cord is in good condition.
Check that the gage wire of the extension cord is the
correct size wire to carry the current this product will
draw.
An undersized cord is a potential fire hazard, and will
cause a drop in line voltage resulting in loss of power
causing the product to overheat. The following table
indicates the correct size cord for length required and
the ampere rating listed on the product nameplate. If
in doubt, use the next heavier gage cord. The
smaller the gage number, the heavier the wire
gage.
It is your responsibility to operate this product at
recommended pressures or vacuum duties and
room ambient temperatures. Do not start against a
vacuum or pressure load.
Start Up
If motor fails to start or slows down significantly under
load, shut off and disconnect from power supply. Check
that the voltage is correct for motor and that motor is
turning in the proper direction. Check the plug, cord
and switch for damage. It so equipped, the thermal
protection switch has tripped, the motor can restart
after cooling.
Grounded Plug Grounding Pin
Grounded Outlet
120-volt grounded connectors
shown. 220/240-volt grounded
connectors will differ in shape.
G 
OPERATION
Minimum gage for extension cords
AmpsVolts Length of cord in feet
120V 25 50 100 150 200 250 300 400 500
240V 50 100 200 300 400 500 600 800 1000
0-2 18 18 18 16 16 14 14 12 12
2-3 18 18 16 14 14 12 12 10 10
3-4 18 18 16 14 12 12 10 10 8
4-5 18 18 14 12 12 10 10 8 8
5-6 18 16 14 12 10 10 8 8 8
6-8 18161210108666
8-10 18 14 12 10 88664
10-12 16 14 10 886644
12-14 16 12 10 866642
14-16 16 12 10 866442
16-18 14 12 8864422

It is your responsibility to:
•Regularly inspect and make necessary repairs to
product in order to maintain proper operation.
•Make sure that pressure and vacuum are released
from product before starting maintenance.
Check intake and exhaust filters after first 500 hours of
operation. Clean filters and determinehow frequently
filters should be checked during future operation. This
one procedure will help to assure the product's perfor-
mance and service life.
1. Remove filter cover.
2. Remove filters and felt (some filters are
held together with a snap fitting). Clean filters
by washing in a non-petroleum based solvent
or soap and water. After cleaning, dry with
compressed air to make sure all moisture is
removed before reinstalling filters.
3. Reinstall felt and filters.
Check that all external accessories such as relief
valves and gauges are attached to cover and are not
damaged before reoperating product.
SHUTDOWN PROCEDURES
It is your responsibility to follow proper shutdown
procedures to prevent product damage. NEVER
ADD OIL TO THIS OIL-LESS PUMP.
Proper shutdown procedures must be followed to
prevent pump damage. Failure to do so may result in
premature pump failure. Gast Manufacturing Rocking
Piston Oil-Less Pumps are constructed of ferrous
metals or aluminum which are subject to rust and
corrosion when pumping condensable vapors such as
water. Follow the steps below to assure correct storage
and shutdown between operating periods.
1 . Disconnect plumbing.
2. Operate product for at least 5 minutes without
plumbing.
3. Run at maximum vacuum for 10 to 15 minutes.
4. Repeat step 2.
5. Disconnect power supply.
6. Plug open ports to prevent dirt or other
contaminants from entering product.
SERVICE KIT INSTALLATION
Gast will NOT guarantee field-rebuilt product
performance. For performance guarantee, the
product must be returned to a Gast Authorized
Service Facility.
c
Disconnect electrical power at the circuit breaker
or fuse box before installing this product.
Install this product where it will not come into
contact with water or other liquids.
Install this product where it will be weather
protected.
Electrically ground this product.
Failure to follow these instructions can result in
death, fire or electrical shock.
WARNING
Electrical Shock Hazard
c
Disconnect electrical power supply cord before
installing Service Kit.
If product is hard wired into system, disconnect
electrical power at the circuit breaker or fuse box
before installing Service Kit.
Disconnect air supply and vent all air lines to
release pressure or vacuum.
Failure to follow these instructions can result in
death, fire or electrical shock.
WARNING
Electrical Shock Hazard
4
Injury Hazard
Product surfaces become very hot during operation,
allow product surfaces to cool before handling.
Failure to follow these instructions can result in
burns, eye injury or other serious injury.
WARNING
Do not direct air stream at body. Air stream from
product may contain solid or liquid material that
can result in eye or skin damage, wear proper eye
protection.
Clean this product in a well ventilated area.

1. Disconnect electrical power to pump.
2. Disconnect air supply and vent all air lines to release
pressure or vacuum.
3. Remove the head bolts and remove head.
4. Remove the cylinder. Remove shims under the
cylinder and remove the two hex head screws on the
retainer plate. Remove retainer plate from cup.
5. Place shims under cylinder, (NOTE: Be sure to
replace all the shims as they are matched to the
cylinder and rod assembly height dimensions) install
over rod assembly.
6. Position cup and retainer plate on top of the cylinder.
With the palm of the hand, gently press retainer and cup
down into cylinder.
7. Align holes in retainer and cup with holes in rod, using
two screws with locking compound (Loctite grade 222)
applied. Reinstall retainer plate and new cup, torque
screws to 30 in. lbs.
Gast finished products, when properly installed and operated under normal conditions of use, are warranted by Gast to
be free from defects in material and workmanship for a period of twelve (12) months from the date of purchase from
Gast or an authorized Gast Representative or Distributor. In order to obtain performance under this warranty, the buyer
must promptly (in no event later than thirty (30) days after discovery of the defect) give written notice of the defect to
Gast Manufacturing Incorporated, PO Box 97, Benton Harbor Michigan USA 49023-0097 or an authorized Service
Center (unless specifically agreed upon in writing signed by both parties or specified in writing as part of a Gast OEM
Quotation). Buyer is responsible for freight charges both to and from Gast in all cases.
This warranty does not apply to electric motors, electrical controls, and gasoline engines not supplied by Gast. Gast’s
warranties also do not extend to any goods or parts which have been subjected to misuse, lack of maintenance,
neglect, damage by accident or transit damage.
THIS EXPRESS WARRANTY EXCLUDES ALL OTHER WARRANTIES OR REPRESENTATIONS EXPRESSED OR
IMPLIED BY ANY LITERATURE, DATA, OR PERSON. GAST’S MAXIMUM LIABILITY UNDER THIS EXCLUSIVE
REMEDY SHALL NEVER EXCEED THE COST OF THE SUBJECT PRODUCT AND GAST RESERVES THE RIGHT,
AT ITS SOLE DISCRETION, TO REFUND THE PURCHASE PRICE IN LIEU OF REPAIR OR REPLACEMENT.
GAST WILL NOT BE RESPONSIBLE OR LIABLE FOR INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
however arising, including but not limited to those for use of any products, loss of time, inconvenience, lost profit, labor
charges, or other incidental or consequential damages with respect to persons, business, or property, whether as a
result of breach of warranty, negligence or otherwise. Notwithstanding any other provision of this warranty, BUYER’S
REMEDY AGAINST GAST FOR GOODS SUPPLIED OR FOR NON-DELIVERED GOODS OR FAILURE TO FURNISH
GOODS, WHETHER OR NOT BASED ON NEGLIGENCE, STRICT LIABILITY OR BREACH OF EXPRESS OR
IMPLIED WARRANTY IS LIMITED SOLELY, AT GAST’S OPTION, TO REPLACEMENT OF OR CURE OF SUCH
NONCONFORMING OR NON-DELIVERED GOODS OR RETURN OF THE PURCHASE PRICE FOR SUCH GOODS
AND IN NO EVENT SHALL EXCEED THE PRICE OR CHARGE FOR SUCH GOODS. GAST EXPRESSLY DISCLAIMS
ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE OR PURPOSE WITH RESPECT
TO THE GOODS SOLD.THERE ARE NO WARRANTIES WHICH EXTEND BEYOND THE DESCRIPTIONS SET
FORTH IN THIS WARRANTY, notwithstanding any knowledge of Gast regarding the use or uses intended to be made
of goods, proposed changes or additions to goods, or any assistance or suggestions that may have been made by Gast
personnel.
Unauthorized extensions of warranties by the customer shall remain the customer’s responsibility.
CUSTOMER IS RESPONSIBLE FOR DETERMINING THE SUITABILITY OF GAST PRODUCTS FOR CUSTOMER’S
USE OR RESALE, OR FOR INCORPORATING THEM INTO OBJECTS OR APPLICATIONS WHICH CUSTOMER
DESIGNS, ASSEMBLES, CONSTRUCTS OR MANUFACTURES.
This warranty can be modified only by authorized Gast personnel by signing a specific, written description of any
modifications.
WARRANTY
5
8. Insert O-ring in groove in cylinder.
9. Install new valve plate, head gasket (note gasket
orientation), and head on cylinder so ports are in
original orientation.
10. Install and snug all head bolts by hand, then in a
cross pattern, torque all three bolts using 20 in. lb.
increments until you reach 70-80 in. lbs. on each bolt.
Before restarting product, check that all external
accessories such as relief valves and gauges are
not damaged.
If PUMP still does not produce proper vacuum or
pressure, send unit to a Gast Authorized Service
Facility for repair.

ROA PARTS ORDERING INFORMATION
Ref ROA-P201-JH
No. Description Qty. ROA-P201-AA ROA-P201-BN ROA-P112-EB ROA-V210-AA ROA-V210-BN
1 Filter Muffler Assy 1 AH190 AH190 B300A AH190 AH190
2 Filter Element 2 AA929 AA929 (1)B344A AA929 AA929
3 Head 1 AJ347 AJ347 AJ347 AJ347 AJ347
*4 Head Gasket 1 AJ404A AJ404A AJ404A AJ404A AJ404A
*5 Valve Plate Assy 1 AJ343A AJ343A AJ343A AJ343A AJ343A
Included valves
6 Valves 2 AF817 AF817 AF817 AF817 AF817
*7 O-Ring Cylinder 1 AH179 AH179 AH179 AH179 AH179
8 Cylinder 1 AJ342 AJ342 AJ342 AJ342 AJ342
9 Shims As AJ345 AJ345 AJ345 AJ345 AJ345
Req.
*10 Cup 1 AH175 AH175 AH175 AH175 AH175
11 Retainer Plate 1 AT715A AT715A AT715B AT715B AT715A
12 Connecting Rod 1 AT846 AT846A AT846N AT846G AT846G
Assy
13 Fan 1 AF533 AF533 AF533 AF533 AF533
14 Grille 1 AH185 AH185 AH185 AH185 AH185
15 Screw 2 AT283 AT283 AT283 AT283 AT283
Service Kit 1 K757 K757 K757 K757 K757
* Denotes parts included in the service kit
Parts listed are for stock model units. For specific OEM models, consult the factory. When ordering parts, please
provide full model and serial model.
6

RAA PARTS ORDERING INFORMATION
Ref RAA-V210-EB RAA-P203-GD
No. Description Qty. RAA-V210-ED RAA-V211-EB RAA-P203-EB
1 Filter Muffler Assy 1 AH190 AH190 AH190
2 Filter Element 2 AA929 AA929 AA929
3 Head 2 AJ343J AJ347R(1) AJ347J
AJ347S (1)
*4 Head Gasket 2 AJ404A AJ404A AJ404A
*5 Valve Plate Assy 1 AJ343A AJ343 (2) AJ343
Included valves AJ343A AJ343A
6 Valves 1 AF817 AF817 AH817
*7 O-Ring Cylinder 2 AH179 AH179 AH179
8 Cylinder 2 AJ342 AJ342 AJ342
9 Shims As AJ345 AJ345 AJ345
Req.
*10 Cup 2 AH175 AH175 AH175
11 Retainer Plate 2 AT715B AT715B AT715A
12 Connecting Rod 2 AT846H AT846J AT846L
Assy
13 Fan 1 AF533 AF533 AF533
13A Fan 1 AF533A AF533A AF533A
14 Grille 2 AH185 AH185 AH185
15 Screw 4 AT283 AT283 AT283
Service Kit 1 K756 & K757 K756 K756 & K757
* Denotes parts included in the service kit
Parts listed ae for stock model units. For specific OEM models, consult the
factory. When ordering pats, please
provide full model and serial model. 7

TROUBLE SHOOTING GUIDE
REASON
LOW
PRESSURE HIGH PRESSURE LOW VACUUM
EXCESSIVE
NOISE
OVER
HEATING WON'T START
Dirty Filter x x
Dirty Muffler x x x
Dirty Valves x x
Damaged Valves x x x x
Worn/Damaged Cup x x
Improper Cylinder
Shimming xxxxxx
Leaky Hose x x
Leaky Check Valve x
Plugged Vac. or
Press. Line xxx xx
Low Voltage x x x x
Leaky Relief Valve x x
We have Gast Authorized Repair Facilities throughout the world. For the most up-to-date listing,
contact one of our sales offices below:
European Sales & Service Headquarters
Beech House Knaves Beech Business Centre
Loudwater, High Wycombe Bucks, England HP10 9SD
Tel: [phone]
Fax: [phone]
www.gastmfg.com
Gast Hong Kong
Unit 12, 21/F, Block B
New Trade Plaza
6, On Ping Street, Shatin
N. T. Hong Kong
Ph: (852) 2690 1008
Fax: [phone]
www.gasthk.com
World Headquarters
P.O. Box 97
2550 Meadowbrook Rd.
Benton Harbor, MI 49023-0097
Ph: 269/926-6171
FAX: [phone]
www.gastmfg.com
www.gastmfg.com
ISO 9001 & 14001 CERTIFIED
®Registered Trademark/™Trademark of Gast Manufacturing Inc., Copyright ©2003 Gast Manufacturing Inc. All Rights Reserved.