Pneumatic Bellows Seal Control Valve with PTFE Lining

Overview

ZJHPF-B pneumatic bellows seal control valve with PTFE lining features a top-guided structure with a compact valve body. The S-shaped flow passage provides low pressure drop, high flow capacity and a wide rangeability. The bonnet adopts a bellows seal construction that completely eliminates the possibility of process medium leaking out through the clearance around the valve stem, which is one of the notable advantages of bellows seal valves. Thanks to the inherent flexibility and outstanding aging resistance of the bellows element, the common weaknesses of packed valves, such as packing aging and sensitivity to temperature changes, are fully overcome. In addition, the bellows-plus-packing double seal construction provides even higher safety and reliability, which is why this valve is widely used in automatic control systems handling highly toxic, strongly corrosive, radioactive and other rare special media.

The large plug guiding area provides excellent vibration resistance. Matched with a ZHA/B multi-spring pneumatic actuator, the valve features a compact structure and high output force.

Features

• Corrosion resistance: resists corrosion by almost all media, including concentrated nitric acid and aqua regia.
• Reliable sealing: bellows plus packing double seal ensures no external leakage.
• Low leakage: the soft-seated plug and seat keep leakage to a minimum.
• High output: the ZHA/B actuator provides large output force with a compact structure.

Actuator Configuration

Model	ZHA-22 / ZHB-22	ZHA-23 / ZHB-23	ZHA-34 / ZHB-34	ZHA-45 / ZHB-45
Effective Area (cm2)	350	350	560	900
Stroke (mm)	16	25	40	60
Spring Range (kPa)	20~100 (standard); 40~200; 80~240; 20~60; 60~100

Valve Body

Item	Description
Body Form	Straight-through single-seat cast globe valve
Nominal Diameter	DN20~150 mm
Nominal Pressure	PN1.6 MPa
Flange Standard	GB/T9113, JB/T79
Connection Type	Flanged (FF, RF, RTJ)
Gland Type	Bolted gland
Working Temperature	-40 °C ~ +180 °C
Packing	V-type PTFE packing

Valve Trim

Item	Description
Plug Form	Single-seat plunger type (PTFE-lined)
Flow Characteristic	Approximate equal percentage

Actuator & Accessories

Item	Description
Actuator Name	ZHA/B multi-spring diaphragm actuator
Actuator Model	ZHA/B-22	ZHA/B-23	ZHA/B-34
Effective Area (cm2)	350	350	560
Stroke (mm)	10, 16	25	40
Spring Range	1.5~3 kg/cm2 (0.15~0.3 MPa)
Diaphragm Material	EPDM reinforced with nylon fabric
Supply Pressure	140~400 kPa
Air Connection	RC 1/4"
Ambient Temperature	-30 °C ~ +70 °C
Optional Accessories	Positioner, air filter regulator, lock-up valve, travel switch, valve position transmitter, solenoid valve, handwheel mechanism, etc.
Action Mode	Air-to-close (B): valve opens on loss of air (FO); air-to-open (K): valve closes on loss of air (FC)

Main Parts Materials

Component	Material
Valve Body & Bonnet	ZG230-450 lined with F46
Valve Seat & Plug	2Cr13 lined with F46; 304 lined with F46
Diaphragm	Nitrile rubber reinforced with polyester fabric
Bellows Material	PTFE

Rated Flow Coefficient Kv & Rated Stroke

Nominal Diameter	G3/4"						20				25	32	40	50	65	80	100	150
Seat Diameter (mm)	3	4	5	6	7	8	10	12	15	20	26	32	40	50	65	80	100	150
Flow Coefficient Kv	0.08	0.12	0.20	0.32	0.50	0.80	1.2	2.0	3.2	5.0	8	12	20	32	50	70	100	240
Rated Stroke (mm)	10										16		25		40			60

Allowable Differential Pressure

Supply Pressure (bar)	Spring Range (bar)	Allowable Differential Pressure (bar)
		Nominal Diameter
		G3/4	20	25	32	40	50	65	80	100	150
1.4	0.2~1.0	16	16	8	5	5	3	2.5	2	1.2	0.8
4.0	0.8~2.4	16	16	16	12	11	7	6.5	4.5	2.8	2.0

Performance Specifications

Item	Specification
Leakage	Less than 0.01% of rated valve capacity
Hysteresis (with positioner)	Less than 1% of full stroke
Basic Error (with positioner)	Within ±1% of full stroke
Rangeability	30:1
Note	Standard V-type PTFE packing is used