MF Type Maintenance-Free Direct Burial Gate Valve for Urban Gas Pipeline Isolation

Buried gas pipelines operate underground for decades, exposed to soil moisture, ground settlement and risks brought by excavation maintenance. Therefore, valves are required to deliver long-term tightness and maintenance-free performance. Every component and sealing structure of the MF maintenance-free gate valve is optimized for gas transmission working conditions.

The core opening and closing component is a fully rubber encapsulated wedge gate. Premium NBR nitrile rubber sourced from well-known overseas suppliers is adopted. Manufactured via precise and scientific vulcanization process, the wedge boasts remarkable resilience, outstanding ageing resistance and durable performance against natural gas medium.

The unique triple stem sealing structure creates multi-layer protection barriers. The sealing assembly can be replaced online under operating pressure. Maintenance can be carried out without venting pipeline gas, cutting downtime substantially and ensuring stable and safe operation of gas pipe networks. 

Designed and manufactured strictly in accordance with CJ/T 514-2018 Metal Valves for Gas Transmission, the valve is suitable for direct burial installation, with operating temperature ranging from -20℃ to 60℃. It is available in PN16 and PN25 pressure grades, covering DN50 ~ DN700 sizes to fit most urban gas distribution pipelines.

Hydrostatic shell test, high and low-pressure sealing test and back seat test all comply with gas valve inspection specifications. Low-pressure sealing test is carried out at 0.5 MPa gas medium, ensuring reliable seal performance even in low-pressure gas distribution networks.

The valve body and bonnet are made of WCB cast steel, while the stem adopts 304 stainless steel. The wedge substrate is ductile iron covered integrally with NBR rubber. All O-rings and gaskets are NBR material, wear-resistant transmission parts use H59 brass, and all fasteners are 304 stainless steel to sustain long-term underground burial.

The MF maintenance-free direct burial gate valve is widely used in municipal natural gas networks, industrial main gas pipelines and underground branch pipelines for residential communities. It supports welding connection with PE gas pipes. Optional accessories including telescopic extended stem, position indicator and anti-theft ductile iron manhole cover can be configured to satisfy different burial depth requirements.