Designed for clean, filtered or strained, non-abrasive liquid service: oils, lubricants, greases, solvents, and most non-fluorinated chemicals compatible with Teflon PTFE seals. Valve is piston-operated, metal-seated without any elastomers. Do not use for extended shutoff service or for extremely low flows (less than 5% of maximum capacity, approximately). Values below the low limit of the spring ranges shown below can be achieved if the flow rates are substantially higher than the minimum 5% of maximum rated capacity. To be on the safe side, a relief valve or bypass valve should always be installed on the outlet side of the regulator (not included with valve). For outlet pressures below the ranges stated below, request model PRH09-FLG double piston model, that is specifically designed to handle the lower outlet pressures that the PRH04-FLG cannot handle. Do not use with liquids that tend to crystallize or solidify under operating conditions. Not for use on steam service as operating temperatures can easily exceed the limitations of the Teflon seals which are rated for 400 Deg F max. Consult factory for steam & gas service.
Features & Benefits
- Pressure-containing parts made from solid bar stock materials — unlike castings which have wall thickness variations.
- Body and trim: Standard material is type 303 or 316 stainless steel. Special alloys (e.g. Hastelloy, Monel, titanium, and Alloy 20) also available.
- Teflon PTFE V packing seals: High-pressure, low-friction, self-expanding design permits operation with small differences between inlet and outlet pressures as low as 50-75 PSI (approx), as long as the packing nut is not overtightened and piston surfaces are kept clean.
- Spring chamber and adjusting spring: These parts are non-wetted, are not in contact with the fluid or gas, and are normally offered in carbon steel, painted for minimal exterior corrosion-resistant protection. When these parts are submerged or located in a corrosive atmosphere, they can be upgraded to a stainless steel or other corrosion-resistant materials at an additional cost. The spring chamber is not offered in aluminum or plastic.
- Standard porting: Right-angle porting, NPT threads (side inlet, bottom outlet). Valve works in any orientation, upright as illustrated, horizontal, etc. See also threaded model PRH-04-FLG.
- Optional porting: Side outlet (parallel port), or in-line porting can be supplied at additional cost when requested.
- Other options: Reduced trim for low-flow applications, locking cap, inlet or outlet pressure gauge ports.