Emerson Shafer User manual

Installation, Operation and Maintenance Manual
PBC-01102001 Rev. A
January 2001
Shafer Poppet Block Control
POWER PILOT EXHAUST OR
RETURN OIL
Normally closed, double three-way poppet valve,
with open exhaust, manual and pilot actuated.
USASI SCHEMATIC

Installation, Operation and Maintenance Manual
PBC-01102001 Rev. A
Table of Contents
January 2001
3
Table of Contents
Table of Contents
Section 1: Introduction
1.1 Basic Construction...........................................................................................4
1.2 Operation........................................................................................................4
Section 2: Basic Check Out Procedures
2.1 Check No.1......................................................................................................7
2.2 Check No. 2 .....................................................................................................7
Section 3: Bill of Material
Section 4: Reconditioning and Assembly
4.1 Reconditioning ................................................................................................9
4.2 Assembly.........................................................................................................9
Section 5: Disassembly of the Poppet Block

January 2001
Installation, Operation and Maintenance Manual
PBC-01102001 Rev. A
4
Section 1: Introduction
Introduction
Section: 1 Introduction
The poppet block is the heart of most Shafer control systems. A double three-way, manual
and pilot actuated, control valve is designed to provide selective directional operation of
Shafer actuators. The poppet block control may direct power gas to a set of gas/hydraulic
tanks (generating hydraulic pressure for powering valve actuators), or it may direct central
hydraulic system pressure directly into a valve actuator. It is engineered to provide reliable
and durable operation and toleration of contaminates in the power source.
1.1 Basic Construction
The poppet block control consists of a double three-way ported valve body containing
two sets of inexpensive, easily replaced nylon poppets to provide tight sealing, poppet
springs, push pins, power and pilot lters, a manual lever assembly and pilot pistons for
remote operation.
NOTE:
For low pressure applications, 350 psi or less, the power poppets item (2) in Figure 1 are
steel backed Neoprene poppets. The exhaust poppets item (3) in Figure 1 are nylon.
1.2 Operation
Spring compression (1) and power gas force the power poppets (2) on their respective
seats and simultaneously hold exhaust poppets (3) in the open position via interconnecting
poppet pins. Tank porting is open to exhaust. The exhaust port is equipped with a check
valve (4) to prevent atmosphere from entering the poppet block assembly.
Figure 1 Neutral Position
FIGURE 1
TANK “A”
POWER PILOT EXHAUST OR
RETURN OIL
TANK “B”
1
2
3
4

Installation, Operation and Maintenance Manual
PBC-01102001 Rev. A January 2001
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Section 1: Introduction
Introduction
Pilot pressure to the pilot piston (5) illustrates force applied to the piston seating the
exhaust poppet and simultaneously unseating the power poppet. Power gas is directed
through tank port "B".
Figure 2 Pilot Activation
FIGURE 2A
TANK “A”
POWER PILOT EXHAUST OR
RETURN OIL
TANK “B”
5
NOTE:
Pilot pressure to the opposite pilot piston shown in Figure 2 will activate the opposite set of
poppets and direct power gas to tank port "A".
Pilot pistons are equipped with an orice in order to vent the pilot pressure and allow the
control to neutralize after stroking an actuator.
Figure 3
High Pressure
Exhaust
Pilot Pressure
Atmospheric Pressure

January 2001
Installation, Operation and Maintenance Manual
PBC-01102001 Rev. A
6
Section 1: Introduction
Introduction
Movement of the lever (7) illustrates force applied by the stem (6), seating the exhaust
poppet and simultaneously unseating the power poppet. Power gas is directed through
tank port "A".
Figure 4 Manual Activation
FIGURE 2B
TANK “A”
POWER PILOT EXHAUST OR
RETURN OIL
TANK “B”
6
7
NOTE:
Movement of the opposite lever shown in Figure 4 will activate the opposite set of poppets
and direct power gas to tank port "B".
Release of the lever will allow the compressed poppet spring and power gas to reseat the
power poppet and simultaneously unseat the exhaust poppet. Power gas pressure
remaining in the gas/hydraulic tank is now vented through port "B" to the exhaust, thus
neutralizing tank and actuator pressures.
Figure 5 Neutralization
FIGURE 3
TANK “A”
POWER PILOT EXHAUST OR
RETURN OIL
TANK “B”

Installation, Operation and Maintenance Manual
PBC-01102001 Rev. A January 2001
7
Section 2: Basic Check Out Procedures
Basic Check Out Procedures
Section: 2 Basic Check Out Procedures
The following two checks illustrate proper working functions of the Shafer Poppet Block.
Failure of any of these procedures may result in operating problems with the valve actuator.
This description is for gas service, but the unit can also be used in hydraulic service.
Figure 6
POWER PILOT EXHAUST OR
RETURN OIL
2.1 Check No.1
There should be zero leakage throughout the control system.
In the neutralized position there should be zero power gas leakage from the exhaust port.
Power gas leakage is usually attributed to debris lodged between the power poppet and seat.
2.2 Check No. 2
Pull the manual lever to full travel and stroke the actuator partially open or closed.
NOTE:
The manual lever for open and close is indicated on the attached tag.
After stroking the actuator partially open or closed, release the manual lever thus
exhausting the gas/hydraulic tank.
After the gas/hydraulic tank is completely exhausted, check the exhaust port for any gas
leakage.
The exhaust port should be free of any restrictions or piping size reductions less than 1/2
NPTF unless factory supplied.

January 2001
Installation, Operation and Maintenance Manual
PBC-01102001 Rev. A
8
Section 3: Bill of Material
Bill of Material
Section: 3 Bill of Material
Figure 7
3
18
29
28 13
12
14
1
20 21
5
23
24
6
25
7
19
27
11
4
8
15 17
26
30
29
10 16
MAXIMUM WORKING PRESSURE 3000 PSI
MAXIMUM TEST PRESSURE 4500 PSI
POPPET TRAVEL 1/16
1/8 NPTF
PILOT PORT
1/4 NPTF
(OPTIONAL)
POWER
STORAGE TANK
1/2 NPTF
POWER PORT
SECTION A-A
1/2 NPTF
EXHAUST PORT
1/4 NPTF
CYLINDER PORTS
1/8 NPTF PILOT
PISTON PORTS
3/8-16 THD.
8
A
2
A
1 1/2
1 1/16
2 5/8
4
7/8 7/82
Table 1
Item Qty. Description Item Qty. Description
1 1 Valve Body 15 2 Piston O-Ring
2 2 Power Poppet Cap 16 4 Piston Back Up Ring
3 2 Filter Cap 17 4 Piston Wear Ring
4 1 Power Connection Cap 18 8 Cap O-Ring
5 1 Exhaust Connection Cap 19 2 Stem O-Ring
6 2 Stem Cap 20 1 Check Valve O-Ring
7 2 Stem 21 1 Check Valve
8 4 Poppet (Nylon) 22 2 Power Poppet Spring
8* 2 Power Poppet (Neoprene)
Exhaust Poppet (Nylon)
23 2 Stem Spring
24 2 "X" Washer
9 2 Poppet Pin 25 2 Stem Boot
10 2 Piston 26 2 Flush Plug
11 1 Strainer (Power) 27 2 Stem Back Up Ring
12 1 Strainer (Pilot) 28 2 Music Wire .018 Dia. x 1"
Lg. S.S.
13 4 Strainer Seal 29 1 Manual Actuation Plate
14 1 Flush Plug 30 3 Actuation Plate Mtg. Bolts
*For low pressure applications.

Installation, Operation and Maintenance Manual
PBC-01102001 Rev. A January 2001
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Section 4: Reconditioning and Assembly
Reconditioning and Assembly
Section: 4 Reconditioning and Assembly
4.1 Reconditioning
Power poppets have a raised boss for poppet spring engagement which may be grasped
with pliers for easy removal. Do not pry poppets off pins with a screwdriver as damage to
seats in the poppet block may result. Remove exhaust poppets from poppet pins.
Figure 8
FIGURE 8A FIGURE 8B
4.2 Assembly
1. Thoroughly clean all components. Inspect seats in poppet block for nicks,
scratches, pitting, etc.
NOTE:
Seat reconditioning may be accomplished by polishing with an emery cloth. Care must be
taken to maintain the radius at the outer edge of the poppet seat.
2. Replace power and exhaust poppets on poppet pins. Poppets may be tapped
lightly into position with a drift pin and light hammer.
3. Check travel of poppet assembly with the scale as shown in (Figure 8B).
Make any adjustment for travel by grinding or ling to shorten the poppet pin or
replace with a new pin if length is needed. Ref: 1/4" drill rod may be substituted
for poppet pins in the 1/4" assembly and 1/2" drill rod for the 1/2" assembly. Adjust
poppet travel to maintain 1/16" min. travel and 3/32" max. travel for both 1/4" and
1/2" assemblies (Poppet block size, 1/4" and 1/2", is designated by the diameter of
the poppet connecting pin.)
4. Inspect and replace O-rings on pilot pistons. Place a small quantity of valve grease
in poppet spring recesses on caps (2) to insure that springs stay in place during
reassembly. Replace poppet block caps (2) insuring power poppet bosses are
engaged properly in poppet springs, replace caps (2), (6), levers, and bracket (29).

10
January 2001
Installation, Operation and Maintenance Manual
PBC-01102001 Rev. A
Section 5: Disassembly of the Poppet Block
Disassembly and Poppet Block
Section: 5 Disassembly of the Poppet Block
Figure 9
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618
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1028
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318
18 3
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18 4
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