BRV71 direct acting bellows pressure reducing valve

Structural characteristic and purpose

This pressure reducing valve is robust direct acting bellows pressure reducing valve designed for use on steam,air and inert industrial type gases.The valve is available in four nominal sizes:DN25,DN32 ,DN40 and DN50. Set the outlet pressure through adjusting spring, the opening of valve flap enlarged when the outlet pressure reduced, the opening of valve flap decreased when the outlet pressure reached to the set pressure. The valve pressure of the medium acts on the area of corrugated tube and transduce to adjusting spring, realizing the function of pressure reducing and regulating.
This reducing valve is designed in meet of the need of energy saving. It has the characteristics of multi-function and light. You can adjust the pressure by rotating the plastic hand wheel, no need to use tool, the connection and installation is very convenient. The internal structure use corrugated tube, the sealing face has filtering mesh protecting device, which protect the internal parts from damage, and greatly prolong the service life.

Working Principle
In operation the valve will modulate as a result of a downstream pressure signal fed through the sensing orifice in the valve stem . This pressure acts on the control bellows generating a force which is balanced by the compressed control spring.The internal forces generated as a result of both upstream and downstream pressures acting on the area of the valve head are minimised by use of a balancing bellows . A graphite reinforced PTFE bush incorporated in both the pushrod/balancing bellows assembly and bottom cap assembly provides two point guiding.

Note: The maximum upstream pressure is 10 bar and it is recommended that the pressure turndown is limited to about 10:1.

BRV71 Screwed NPT connections
BRV73 Flanged PN16,ANSI 150 or JIS 10 connections.

The BRV71 and BRV73 are supplied with one of three colour coded springs:
Grey:                               for pressure control                                 0.14 to  1.7 bar g
Green:                            for pressure control                                 1.4   to   4.0 bar g
Orange:                         for pressure control                                  3.5  to    9.0 bar g