Pressure Differential Sustaining Valve

Pressure Differential Sustaining Valve

Model 106-RPS-D & 206-RPS-D

The valve shall be installed in-line. It shall automatically open when the pressure differential across the valve exceeds the pilot setting. When open the valve modulates to limit the flow through the valve in order to maintain the desired pressure differential.

Specifications

Model 106-RPS-D & 206-RPS-D Pressure Differential Sustaining Valve

The valve shall be a Singer model 106 (206) – RPS-D, Pressure Differential Sustaining valve, size ____” (mm), ANSI Class 150 (300) flanged (screwed), globe (angle) style, with ANSI B16.42 pressure rating of 250 (600) psi. The valve shall be installed in-line and automatically open when the pressure differential across the valve meets or exceeds a pre-determined (adjustable) setting.

The main valve shall be constructed of ASTM A536 ductile iron and coated inside and out with an NSF61 approved fusion epoxy. The valve stem and seat ring shall be constructed of stainless steel. The valve shall come complete with Model 81-RPD pressure differential pilot, spring range 20 to 200 psi, (5 to 25, 10 to 80, 100 to 350) factory set at _____ psi. The pilot system shall be assembled according to Schematic A0428.

Prior to shipment, the standard tests shall include a pressure test and a full function, operational test. The entire valve shall be covered by a three (3) year limited warranty against defects in materials and workmanship. The stainless steel seat ring shall be covered by Singer Valve’s exclusive LIFETIME replacement warranty.

Function:

The valve shall be hydraulically operated, globe (or angle) pattern and installed in-line. It shall automatically open when the pressure differential across the valve exceeds the pilot setting. When open the valve modulates to limit the flow through the valve in order to maintain the desired pressure differential

Main Valve Characteristics:

All valves shall be constructed of ASTM A536-65/45/12 ductile iron, rated to ANSI Class 150 or Class 300 maximum operating pressures of 250 psi and 600 psi respectively. Every valve shall come internally lined and externally coated with an NSF61 approved fusion epoxy coating. All repairs shall be possible without removing the valve from the line.

The inner valve assembly shall be top and bottom guided by means of easily replaceable bearing bushings. The inner assembly shall be the only moving part and securely mounted on a stainless steel stem with wrench flats to simplify assembly. Each stem shall be machined ready to accept the optional position indicator or limit switch assembly. The inner valve assembly shall operate in the vertical plane and seal perpendicular to the seat.

For smooth “frictionless” motion, actuation shall be by diaphragms, either flat or rolling type, constructed of nylon fabric, bonded with synthetic rubber. The diaphragms shall not be used as a sealing surface. All diaphragms shall meet or exceed a Mullen Burst Test of 1500 psi. No lip seals, o-rings or packing may be used to seal the actuator.

The seating shall consist of a mechanically held, rectangular cross-section, synthetic rubber resilient disc and an erosion resistant, stainless steel stationary seat. The seat shall be bolted into place and have a warranty for the life of the valve. No special tools will be required to work on any part of the valve.

The valve cover shall have a separate removable spring cap giving access to the stem for alignment check and ease of assembly.

Each valve shall be tested prior to shipment. The shop tests shall include a pressure test and a functional operational test. Pilots shall be preset as specified. All valves shall come with a three (3) year warranty and an exclusive LIFETIME replacement warranty for the stainless steel seat.

Pilot System Characteristics:

The main valve shall be complete with a fully functional pilot system assembled according to Schematic A0428.

The pilot system shall include the model 81-RPD direct acting, spring and diaphragm actuated pressure differential pilot. This normally closed pilot is constructed of ASTM B16 brass with stainless steel seat and Buna N diaphragm and seals. It shall have a spring range of 20 to 200 psi (5 to 25, 10 to 80, 100 to 350) and be factory set to XXX psi.

The pilot system shall come complete with the following ancillary components:
a) Model 852-B closing speed control needle valve.
b) Pilot system strainer with 40 mesh stainless steel screen and a built-in blowdown/cleaning port.
c) Isolating ball valve(s) standard at downstream connection of pilot system on all sizes. (Inlet and bonnet isolation ball valves are also standard on valves 4” and larger)