Summary of Product Characteristics

QCSY series Y-type pneumatic trap valve is designed as a new generation steam trap valve according to the requirement of the thermal 
power plant hydrophobic system and has the advantage of low cost and high temperature and pressure resistance compared with the 
pneumatic ball valve, butterfly valve and gate valve. It can be used in inflammable and explosive occasions. Close or open the valve 
according to the signal of control system or adjusting instrument to discharge mixture of condensed water and steam in the system pipe-
line.
The product is widely used in the remote control of thermal power plants and other industries. Its role is to discharge mixture of steam 
and water in the steam pipeline of each section in the start phase of thermal power plant until steam turbine runs normally. Trap valve 
should be closed to reduce energy waste when power unit runs normally. Open the trap valve according to the procedure when it 
doesn´t work, steam and water in the pipeline should be discharged to ensure safety of system.
The trap valve is different from normal trap valve. The function of normal trap valve is to block steam and 
drain water. QCSY series pneumatic trap valve is to discharge the mixture of steam and water in the piping.

Typical Characteristics:
01. Valve body is integral forging forming which is safe and reliable with good tensile strength and compressive strength performance
02. Y-type structure, medium is approximate to a straight line through the flow path, small fluid resistance, high Kv value 
03. The sealing of valve core and seat is overlaying stellite alloy to prevent from cavitation, erosion and abrasion resistance.
      It has long service life
04. There are two guide rings on the valve core. The stem is stressed evenly and has flexible action. It's hard to cause jam
05. The integral welding type or removable type structure of seat can be chosen. Maintenance and replacement of detachable
      valve seat is more convenient
06. Sealing surface is precisely machined. Leakage level is above Ⅳ, small leakage (small diameter valve is nearly zero leakage)
07. Applicable temperature: Normal Ia: -29～250℃
                                              special Ⅲa: -29～350℃,Ⅲb: -29～450℃,Ⅳa: -29～595℃
08. Valve body material: Forged steel (code: [C]), forged SS304 (code: [B])
                                       Forged chrome-molybdenum vanadium steel (code: [V]), forged SS316 (code: [R])

 Structure Diagram

Brief Instruction of Order Model

Note: For details, please refer to the model code instruction of control valve type direct stroke automatic control valve on P003 of this manual.

Main Component Material Table

Main Technical Parameters

External Dimension and Weight

Notes:

1. The data in the table above is the dimension and approximate reference weight of valve whose nominal pressure is ≤Class 900Lb, which shall be based on the actual product.
2. The connection type is normally the butt welding type, butt welding end is made according to ASME B16.25 standard, can also be  customized, according to users´requirements, such as socket welding type, flange, etc.

Special Configuration

QCSY81 Series Pneumatic Diaphragm Type / QCSY51 Series Pneumatic Plunger Y-Type Pneumatic Trap Valve

Product Overview

The BEST AUTOVALVE QCSY Series Pneumatic Y-Type Trap Valve is designed for steam and condensate drainage in thermal power plant steam systems and other industrial applications. It operates according to signals from a control system or regulating instrument, opening or closing to discharge the mixture of steam and condensed water from pipelines.

Unlike conventional steam traps, which are designed to block steam and drain condensate, the QCSY pneumatic trap valve is designed to discharge the mixture of steam and water from the piping system. During the start-up phase of a thermal power plant, it helps remove accumulated steam and water from steam pipelines. Once the steam turbine reaches normal operation, the trap valve can be closed to reduce energy waste. It can also be opened according to operating procedures when pipeline drainage is required for system safety.

The product is available in QCSY81 pneumatic diaphragm type and QCSY51 pneumatic plunger Y-type configurations.

Key Features

• Forged Valve Body: Integral forging construction provides reliable strength and tensile and compressive performance.

• Y-Type Flow Passage: The flow path is approximately straight, helping reduce fluid resistance and provide a high Kv value.

• Wear-Resistant Sealing Surfaces: The valve core and seat sealing surfaces are overlaid with Stellite alloy to improve wear resistance and service life.

• Guided Valve Core: Two guide rings on the valve core help distribute stem loading evenly and support smooth operation while reducing the risk of jamming.

• Flexible Seat Construction: Available with an integral welded seat or a removable seat design. The removable seat facilitates maintenance and replacement.

• Controlled Leakage Performance: The specified leakage level is Class IV; leakage is very low, and is nearly zero for small-diameter valves.

• Remote Operation: Opens or closes in response to signals from a control system or regulating instrument.

• Industrial Applications: Suitable for use in inflammable and explosive operating environments when configured with the appropriate accessories.

Valve Body Materials

The QCSY series offers several forged body material options:

The valve seat, valve core, guide sleeve, bonnet, stem and other internal components use material combinations specified for each material configuration. Stellite alloy overlay is specified for the valve seat and valve core sealing surfaces.

Technical Specifications

Flow Capacity by Nominal Size

Temperature and Pressure Options

The standard temperature range is -29°C to 250°C. Special configurations are available for higher-temperature service:

• Heat-dissipation type: -29°C to 350°C for carbon steel configurations.

• Heat-dissipation type: -29°C to 450°C for stainless steel configurations.

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

The standard nominal pressure is 16 bar. Other pressure classes include 25, 40, 63 and 100 bar. The manual also lists ANSI Class 150, 300, 600, 900, 1500, 2500, 3500 and 4500 pressure ratings. Final selection should be based on the actual material, temperature and pressure configuration.

Pneumatic Actuator and Control Options

The ordering information identifies BT280 and BT400 actuator configurations. The valve can also be supplied with optional control and accessory configurations, including:

• Normally closed action.

• AC220V solenoid valve.

• Explosion-proof solenoid valve.

• Normal or explosion-proof travel switch.

• Handwheel mounted on top.

• Explosion-proof accessory configuration.

The normal solenoid valve and explosion-proof solenoid valve are identified as separate options in the ordering code.

Applications

The QCSY pneumatic Y-type trap valve is designed for steam and condensate drainage in:

• Thermal power plant steam pipelines.

• Steam turbine start-up and shutdown systems.

• Industrial steam piping systems.

• Applications requiring controlled discharge of steam and condensed-water mixtures.

Installation and Maintenance

The valve can be installed at any angle. For horizontal installation, the actuator should face upward to help extend service life. The standard connection is butt welding, with butt-welding ends manufactured according to ASME B16.25. Socket-welding and flange connections can be customized according to user requirements.

The removable valve-seat option provides convenient access for maintenance and replacement.

Warranty

BEST AUTOVALVE provides a one-year warranty under the technical conditions specified in the instruction manual, effective from delivery. Faults caused by improper user operation or installation are excluded from warranty coverage; technical assistance is available to help resolve such issues.