Product Description:

Pneumatic piston type cut-off valve (short piston type cut-off valve) is the execution unit in the pneumatic unit combination instrument. It receives signals from regulating instruments to control the cutting and connection or switching of fluid flow channels in the process pipeline. This product has the advantages of high operating force, innovative valve body design, low flow resistance, high rated flow coefficient, large allowable pressure difference, and excellent sealing performance. Therefore, it is widely used in automatic and remote control systems for production processes in industrial sectors such as petroleum, chemical, metallurgical, power, and textile.
Structure and principle: The pneumatic piston type cut-off valve consists of two parts: a pneumatic piston type actuator and a straight stroke adjustment mechanism, which are connected by a bracket edge in the middle. According to the form of the regulating mechanism, pneumatic piston type cut-off valves can be divided into three types: straight through single seat cut-off valves (ZSQP type), straight through sleeve cut-off valves (ZSQM type), and two position three-way cut-off valves (ZSQN type). There are two types of pneumatic piston actuators: single acting (spring reset) and double acting (double intake). Adopting a single acting actuator, the overall operation mode of the machine can be divided into air closed (horizontal pipeline connection) and air open (horizontal pipeline disconnection). Pneumatic piston shut-off valves have two sealing forms: hard seal and soft seal, which are suitable for different temperatures and pressures.
The ZSQM pneumatic piston sleeve cut-off valve adopts a balanced valve core, which can increase the cut-off pressure difference.
The two position three-way cut-off valve adopts a four-way valve body with three flow ports, which is particularly suitable for switching between two flow paths.
Working principle: When the signal pressure is zero, the valve core is in its initial state (normally open or normally closed) due to the preload force of the spring (single acting only). When the actuator receives a signal pressure (0.4~0.6MPa), the compression spring drives the push rod, valve body, and valve core to move to the limit position, making the valve fully open or fully closed. To achieve control over the connection, disconnection, or switching between pipelines for the medium inside the pipeline. Equipped with a two position three-way electric sample valve, the piston type cut-off valve control is more convenient and simple.

Material of parts:

Valve body and cover: HT200, ZG230-450, ZG1Cr18Ni9Ti, ZGOCr18Ni12Mo2Ti
Valve seat: 1Cr18Ni9Ti Cr18Ni12Mo2Ti
Valve core: 1Cr18Ni9Ti Cr18Ni12Mo2Ti
Cylinder block: ZG230-450
Piston: ZAlSi12
Packing: polytetrafluoroethylene, flexible graphite
Soft sealing element for valve core: reinforced polytetrafluoroethylene

Technical parameters:

Size and weight:

Connection standard:

Flange standard: Cast iron flange GB4216.5-84
Cast steel flange GB9113-88, JB/T79-94
Flange sealing surface type: PN16 is convex; PN40 and PN64 are concave convex surfaces, and the valve body is concave.
Structural length: GB12221-89
Execution mechanism signal interface: M10 × 1
*The distance between the valve body flange and the flange end face can be manufactured according to the standard specified by the user. For example, ANSI JISJPI and other standards.

Ordering Notice:

Please provide the following information when placing an order:
Nominal diameter (mm)
Nominal pressure (MPa)
Rated flow coefficient (Kv)
upstream pressure
Cut off pressure difference
Media name
Working temperature and range
Operation mode of the whole machine
Valve body, valve internals, and packing materials
Attached attachments
Other special requirements