Fulflo Relief Valves

Established in 1912, Fulflo was incorporated in 1933 under its present name and trademark.  Patents for the original guided piston, direct-acting relief valve were obtained in 1935, coincident with the onset of fluid power systems.

Application

The Fulflo "V" Series range in size from 3/8" through 2" and operate efficiently with liquids of any viscosity at pressures from 2 to 1000 PSI.  The "V" Series valves are available in flange or screw type...cartridge or handwheel in a choice of brass, cast iron, steel and stainless steel.

Installation

Fulflo valves can be mounted in any position.  A tee may be inserted in the pump discharge line to mount the valve.  The correct size of valve should be installed, preferably matching the pump discharge line.  Screw the valve into the nipple in the tee, or in the case of the flange style, bolt the valve to the companion flange screwed into the nipple.  When the valve is used for frequent bypassing of oil pressure, its outlet should be piped back to the tank.  Care must be taken to have the discharge well below the oil level in the tank to prevent air entrainment and erratic operation.

Only if the valve is used as safety or overload relief and operates infrequently may its discharge be piped back into the pump suction line.  Frequent or continuous operation under these conditions will cause excessive heating of the oil and possible damage.

Setting Valves

Valves 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.  Adjust valve adjusting screw until valve slightly bleeds at the set bypass pressure and lock adjusting screw.

Fulflo valves are not designed to be positive shut-off, and will pass a minimal amount of leakage before the set pressure.  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 adjusted for cracking pressure as above, continue closing bypass until the required flow resister on the flow meter and observe pressure.  Re-adjust pressure, if necessary, to obtain desired pressure at desired flow.

Maintenance

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.

SUPPORT DOCUMENTS V-Series General Brochure

 

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