Models
AAPF: Cast Iron
ACPF: Cast Steel
ASSPF: Stainless Steel
- API 520 & 614 Approved
- Chatter-free operation
- Mount in any position
- Suitable for continuous duty
Size Range: 2.5″, 3″ and 4″
Pressures: 50 – 500 psi
Flow Rate: 150 – 600 gpm

INSTALLATION, MAINTENANCE & OPERATION
Installation
Fulflo valves can be mounted in any position. A tee may be inserted in the pump discharge line to mount the valve. The pipe lines carrying the heavy valves must be well supported and overhung weights avoided. The correct size of valve must be used, preferably equal to the size of the pipe line to which they are connected. Flanged valves (AADF and ACDF) are bolted to the companion flange which may be threaded or welded to the pipe. The outlet of the valve should be piped to the supply tank, unless specific applications call for alternate piping of return lines. Care must be taken to have the discharge well below the oil level in the tank to prevent air entrainment and erratic operation.
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Setting Valves
Valve may be set with a hydraulic hand pump for cracking pressure. If a test stand is available, valve should be connected to the discharge header with the pump bypass open, and the bypass gradually closed until the desired pressure registers on the gauge. For Internal Pilot Operated valves, adjust valve adjusting screw until approximately 5-7 GPM is flowing through the valve, at that point the main piston will open and then the valve will be considered at the set point, then lock adjusting screw. If a valve is required to bypass a given amount of fluid at a given pressure, a test stand having a flow meter in the pump discharge line must be available. With a valve adjusting for cracking pressure as above, continue closing bypass until the required flow registers on the flow meter and observe pressure. Readjust pressure, if necessary, to obtain desired pressure at desired flow.
Maintenance & Operation
Fulflo valves provide reliable “chatter-free” operation when the system is free of abrasives and foreign matter. Continuous filtration of the liquid used is strongly recommended.
TYPICAL DISASSEMBLY OF STANDARD TYPE VALVE
To dismantle valve for inspection or cleaning:
- Remove cap “A” and gasket “D”
- Remove nut “C”
- Remove adjusting screw “B”
- Remove cap screws “E”
- Remove bonnet “F”
- Remove gasket “G”
- Remove pilot spring “J”
- Unscrew and withdraw cylinder “M” (do not unscrew cylinder retainer “L” until this step is complete)
- Unscrew and remove cylinder retainer “L” (after removing cylinder “M”)*
- Unscrew and remove piston retainer “K”
- Remove retaining ring “H”
- Remove pilot piston “N”
- Remove balance spring “O”
- Remove piston “P”
- Remove retaining bushing “S” if necessary
*CAUTION: Hold in vise–balance spring “O” is under heavy compression
Inspect bores of both piston retainer “K” and cylinder “M”. Inspect pistons “N” and “P” for wear or scoring. Replace broken or damaged parts. Clean all parts thoroughly and re-assemble as follows:
- Reverse process of disassembly from operation 15 to 6 above
- Thread adjusting screw “B” into bonnet “F”, while re-assembling bonnet “F” to body “R”
- Then proceed with steps 5, 4, 2 & 1, above, in reverse order.

ASSEMBLY NUMBER ID CHART
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Example

How to Order
Specify:
- Valve Model Number (1-10)
- O-Ring Identification Number (11)
- Piston Material (12)
- Spring Part Number (13)
- Spring Pressure Range or Desired Pressure Setting (14)
DIMENSIONS & PARTS
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Cutaway Drawing

Parts List

+ Recommended spare parts
* See Assembly Number Identification Chart; Symbol Number 13
PERFORMANCE DATA
All valve tests 110˚F to 120˚F Oil Viscosity 150 SSU at 100˚F
(Charts good from 30 to 500 SSU)
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Overpressure: The pressure increase or accumulation above the set pressure when the valve is discharging flow.

