Features

01. This valve is equipped with a single acting or double acting piston actuator, which receives a greater supply pressure
      than the diaphragm actuator, thus having a greater output force
02. Compared to diaphragm actuators, they are more suitable for use in high temperature and high pressure occasions
03. Special configurations: 
      Q56/Q55-Ds---equipped with top mounted handwheel, Q56/Q55-Cs---equipped with side mounted handwheel
      Q56/Q55-◆---equipped with limit switch (valve position signal output)

Basic Structure Diagram

Main Component Material Table

Main Technical Data

Note: Applicable temperatures for bellows sealed type (℃), normal Vd:-29～350, special Va:-29～150 (PTFE sealing), 
          Vc:-29～250 (PPL sealing), Ve:-60～-100, Vf:-100～-196.

External Dimension and Weight

Notes:

1. The unit of nominal pressure PN in the above table is bar. 
2. The weight in the table is standard type data without accessories.                
3. The flange is manufactured according to JB/T79-1994 standard by default, and can also be manufactured according to the standardsspecified by the user, such as GB/T9124, HG/T20592, ANSI, JIS, DIN, etc.

Q56 Single Seated / Q55 Sleeve Pneumatic Piston Cut-off Valve

The BEST AUTOVALVE Q56 Series Single Seated and Q55 Series Sleeve Pneumatic Piston Cut-off Valves are designed for automatic shut-off and flow control in industrial process systems. They are equipped with single-acting or double-acting pneumatic piston actuators, providing greater output force than diaphragm actuators. The piston actuator configuration is suitable for applications requiring higher operating force and is described in the manual as more suitable for high-temperature and high-pressure environments.

Key Features

• Pneumatic piston actuation: Available with single-acting or double-acting piston actuators to meet different control requirements.

• Two valve construction options: Q56 single seated type and Q55 sleeve type.

• Manual operation options: A top-mounted or side-mounted handwheel can be specified.

• Position signal output: An optional limit switch is available for valve position feedback.

• Multiple bonnet configurations: Normal, cryogenic, heat dissipation, high-temperature and bellows-sealed types are available.

• Flexible actuator control: Single-acting normally closed, single-acting normally open and double-acting modes are optional.

• Configurable air-failure position: The valve can be configured to open, close or hold its position when the air supply fails.

Technical Specifications

Rated Flow Coefficient

Materials

The valve body and bonnet can be supplied in WCB, CF8, CF8M or CF3M. Valve core and seat materials include SS304, SS316 and SS316L, with Stellite alloy or PTFE overlay options. Valve stem materials include 2Cr13, 17-4PH, SS304, SS316 and SS316L.

The standard packing material is PTFE for temperatures from -196°C to 150°C, with flexible graphite specified for temperatures above 150°C. The cylinder spring is normally 60Si2Mn, with 50CrVA available as a special option. The cylinder piston is made of aluminium alloy, and the cylinder O-ring is normally NBR, with VITON available as a special option.

Leakage Performance

The manual specifies different leakage levels for the two valve constructions:

• Q56 single seated type: Normal leakage level IV; special leakage level VI.

• Q55 sleeve type: Normal leakage level III; special leakage levels IV and VI.

The manual also lists hard sealing at level IV and soft sealing at level VI in its general technical data. The applicable leakage class should therefore be confirmed for the selected valve construction and sealing configuration.

Bonnet and Temperature Options

The available configurations include:

• Normal type: Hard-sealing working temperature range of -29°C to 150°C as standard, with a special option up to 250°C.

• Cryogenic type: Options covering -60°C to -100°C and -100°C to -196°C.

• Heat dissipation type: Temperature ranges of -29°C to 350°C or -29°C to 450°C.

• High-temperature type: -29°C to 595°C.

• Bellows-sealed type: Temperature range depends on the selected bellows sealing material, with options listed from -100°C to 350°C.

Actuator and Accessories

The actuator can be configured for single-acting normally closed, single-acting normally open or double-acting operation. A handwheel can be installed on the top or side of the valve. Optional accessories include a solenoid valve, passive contact travel switches, an electromagnetic induction switch, an air filter pressure-relief valve and a limit switch for valve position signal output.

When a solenoid valve is selected, the manual lists AC220V 50/60Hz as the normal supply voltage and DC24V as an option, with an allowable voltage tolerance of ±10%. The listed explosion-proof options are ExmbⅡCT4 and ExdⅡCT6. Protection grades are IP65 as standard and IP67 as a special option.

Applications and Configuration

The Q56 single seated and Q55 sleeve pneumatic piston cut-off valves can be configured according to the process medium, flow rate, design pressure, operating temperature, inlet and outlet pressures, and medium density. The final valve selection should be based on the actual operating conditions and the required flow and shut-off performance.

For configuration and quotation, please provide the medium, required flow rate, design pressure, medium temperature, inlet and outlet pressure, medium density, nominal size, nominal pressure, connection standard, required leakage level and actuator control mode.

Manufacturer: Shanghai Best Automation Technology Co., Ltd.
Brand: BEST AUTOVALVE