Welcome to the official website of Zhejiang Dongda Pump & Valve Co., Ltd.!
Zhejiang Dongda Pump & Valve Co., Ltd. Tel 0577-67961597 / 13806834846

Focus on flat gate valve for 26 years

We specialize in the production of flat gate valves, pneumatic shut-off gate valves,
parallel double gate valves, oilfield special valves, etc.


Position:HOME>PRODUCTS>Pipeline flat gate valve
Z44WY parallel double gate valve

Z44WY parallel double gate valve

产品分类:Pipeline flat gate valve
Product Categories:Pipeline flat gate valve
Sales Hotline:0577-67966500
Order Now Contact online
Product Details

product description:

Parallel double gate valve is suitable for Class150~900/PN1.0~16.0MPa, working temperature -29~550℃ for oil and gas refining equipment engineering, aiming at ordinary wedge gate valve under high pressure and high temperature, the gate deformation is not tight and the seal is not tight. The optimized design of leakage is currently a new, mature, stable, and technologically advanced mainstream product in petroleum refining projects, and is an ideal product recognized by various design institutes and project units.

Application range:

The flat gate valve is suitable for natural gas, petroleum, chemical, environmental protection, urban pipelines, gas pipelines and other transportation pipelines, venting systems and steam storage devices, as opening and closing equipment.

1. For oil and natural gas pipelines, use single or double gate flat gate valves. If you need to clean the pipeline, use single or double gate open-rod flat gate valve with diversion holes.


2. For the transportation pipeline and storage and transportation equipment of refined oil, select single gate valve without diversion hole or light flat gate valve.


3. For oil and natural gas extraction wellhead devices, single-gate or double-gate flat gate valves with dark rod floating valve seats and diversion holes are used, most of which are API16A standards, and the pressure levels are API2000, API3000, API5000, API10000, API15000, API20000.

 (2 1/16”- 7 1/16” 2000-20000 PSI PR1. PR2 PSL1-PSL4 AA. BB. CC. DD. EE. FF)

4. For pipelines with suspended particles, use hard-sealed flat gate valves or knife-type flat gate valves.


5. The city gas transmission pipeline uses a flat gate valve dedicated to buried gas with a dark rod.


6. For urban tap water projects, single-gate soft-sealed open-rod flat gate valve is selected.


Structural features:

The parallel double gate valve adopts a metal hard seal structure; the gate adopts a combined form, and the seat sealing surface adopts a hard sealing material directly on the valve body, so as to ensure that the valve body is sealed without any leakage when the valve is closed.

When the valve is opened, the valve stem drives the wedge to move upward, so that the sealing surface of the gate is away from the sealing surface of the valve body, so that there is no relative friction between the sealing surfaces during the opening process, which improves the service life of the valve.

When closing, the sealing surface of the ram and the sealing surface of the valve body fit together. When the ram continues to close, the ram does not move and the inclined block moves downward to force the ram to press against the sealing surface to form a reliable seal.

The valve with this structure can achieve two-way sealing and good sealing performance; at the same time, the opening and closing torque is small.

A gate guide structure is designed inside the valve body to ensure accurate positioning of the gate. The valve with this structure has a long service life; it is safe and reliable.

1. When the output force of the actuator acts on the main spool through the valve stem, it is designed at a certain angle. The main spool is converted into horizontal left and right forces, and then through the secondary spool, the sealing disc presses the two valve seats to form a double Negatively broken seal, the seal does not leak, the torque is small, and the sealing joint surface of the switch valve has no friction, which fundamentally solves the problem of the valve core stuck or cannot be opened in the valve body.

2. The pneumatic actuator adopts a piston type mechanism, and the solenoid valve is used as a switching element to control the air intake and exhaust of the upper and lower parts of the cylinder to control the vertical up and down displacement of the opening and closing parts, and to control the opening and closing of the valve.

3. Equipped with a feedback device to send valve switch-like signals, solenoid valve realizes remote control, centralized control, automatic control, and on-site operation.

4. Pneumatic actuator, flexible and reliable pneumatic --- manual rotating mechanism, directly carry out the conversion process from pneumatic to manual or manual to pneumatic operation mode.

5. The on-site indication of the valve opening and closing status, the upper extension shows the rising and falling of the indicator rod, and it marks when the valve is fully open (extends indicating high position), and when the valve is fully closed (extends indicating rod low position).

6. Single-acting pneumatic device or air tank series with spring reset to ensure the power supply, automatic switch when the air supply fails, safety, reliability, speed, environmental protection and energy saving.

Standard Specification:

Design and manufacturing standards: GB/T 12234

Structure length standard: GB/T 12221

Connecting flange standard: ASME B16.5 HG/T 20592

Pressure and temperature rating: ASME B16.34 GB/T 12224

Test inspection standard: GB/T 13927

Parts materials and working conditions:

Part Name

Parts materials

GB/T 12234




A216 WC9

A351 CF8C




A182 F22+STL

A182 F16+STL






Valve seat



A182 F22+STL

A182 F316+STL


Flexible graphite


Flexible graphite/304




A193 B7M+Zn

A193 B7M+Zn

proper temperature





Applicable medium

Refining oil

Refining oil

Refining oil



If you have any questions about quotation or cooperation, please feel free to contact us by phone 0577-67966500 or use the enquiry form below. Our sales representative will contact you within 24 hours. Thank you for your interest in our products.

Copyright © 2015 Zhejiang Dongda Pump Valve Co., Ltd. All Rights Reserved   备案号:浙ICP备2023007718号-1浙公网安备 33032402002076号网站统计