Self-operated/regulating Pressure Flanged RF SS304 SS316 Control Valve

Self-operated pressure control valve is composed of body assembly, actuator, positioning spring ,stainless steel bellows, external pressure tap and all that. The valve doesn’t requires any auxiliary energy from external supply sources, by use of medium itself pressure as motive power, it can automatically control and stabilize the medium pressure.
It may be suitable for steam, non-corrosive gas , liquid and steam in various process systems.
Main features:
1 Pressure balance function ensure high sensitivity
2 Reliablyhandling with low noise and free maintenance
3 standard modular design
4 it has multiple composite controls through combinations of different components

Standard Specifications

Body Type :cast globe valve, (as shown in figure 1)
Nominal diameter :DN20,25,32,40,50,65,80,100,125,150,200,250,300
Nominal pressure : GB PN1.6,2.5,4.0MPa
ANSI150,300
JIS 10K,20K,30K
DIN PN16,PN25,PN40
End connection: flange HG20596-97M,FM; ANSI B16.5 RF ;DIN2543/2544/2545RF;JIS B2201RF
Face to face dimension: please refer to table 2
Body material: WCB,ZG0Cr18Ni9(CF8),ZG0Cr18Ni12Mo2Ti(CF8M)
Bonnet type: STD type,-10～80℃；Middle temp. type(with condenser ), ≤250℃;High temp. type(with condenser and extensions),≤350℃
Packing material: V shape PTFE, flexible graphite, o-rings
Seal gasket : Spiral wound gasket, Graphite with metal gasket, Zigzag gasket, Flat gasket.
Paint: Carbon steel shell surface required to paint, stainless steel or copper surface without paint .

Trim Plug type :Parabolic pressure balance plug, cylinder pressure balance plug, parabolic double seat pressure balance plug
Flow characteristics: Quick opening
Plug material:0Cr18Ni9(304),0Cr17Ni12Mo2(316)
Seat material::0Cr18Ni9(304),0Cr17Ni12Mo2(316),304+F4,316+F4
Stem material:0Cr17Ni4Cu4Nb(17-4PH),0Cr17Ni12Mo2(316)
Push rod material:2Cr13(420),0Cr17Ni12Mo2(316)
Bellows material:0Cr17Ni12Mo2(316),00Cr17Ni14Mo2(316L)
Actuator
Type : Multi-spring diaphragm or cylinder piston
Pressure Regulating Range: Please see table 1
Upper and Lower Case Material:A3,A4 With PTFE,0Cr18Ni9(304)
Diaphragm Rubber: NBR , EPDM , FPM and other oil-resistance rubbers
Cylinder Material: 20,0Cr18Ni9(304),0Cr17Ni12Mo2(316)
Piston Material :aluminum alloy
Spring Material: 60Si2Mn
Work temperature:-20～80℃

Performance
Control Type: Pressure relief type (K), pressure regulator type (B)
Rated Cv: As shown in table 1
Pressure Control Precision : ± 3%.
WorkingTemp:-10～350℃
Rated Travel: see table 1
Shape Size: As shown in figure 3, table 2
Weight of product: As shown in table 2

Principle of operation
1. Pressure regulator type
The process medium flows through the valve in indicated direction.The position of the valve plug determines the flow rate between the free area formed by plug and seat.The downstream pressure to be controlled is transmitted via pressure tap to the operating diaphragm where it is converted into a positioning force. This force adjusts the valve plug as a function of positioning spring force.the spring force can be adjusted using the set point nut.The pressure balanced structure can balanced out the forces created by the upstream pressure and acting on the valve plug.The downstream pressure is balance via the diaphragm area in the actuator.
2. Pressure relief type
The process medium flows through the valve in indicated direction.The position of the valve plug and the area released between plug and seat determine the flow rate. The operating diaphragm is tensioned by positioning spring and set point nut,so that the valve is closed by the spring force before relieved of pressure. The upstream pressure to be controlled is transmitted via pressure tap to the operating diaphragm where it is converted into a positioning force. This force is used for moving the vlave plug up according to the force of the positioning spring.When the force resulting from the upstream pressure rises above the adjusted set point, the valve opens propotionally to the change in pressure. Upstream and downstream pressures acting on the plug are balanced.