Definition of High-Temperature and High-Pressure Needle Valve

The high-temperature and high-pressure needle valve is a special valve used in industrial fields such as chemical engineering, electric power, and petroleum. It adopts a tapered sealing structure and is made of high-temperature resistant materials, with a maximum operating pressure of up to 689 bar and a temperature resistance range from -54℃ to 649℃. This valve includes various connection types such as welded type and ferrule type, and is equipped with manual/pneumatic/electric actuators. It ensures effective medium isolation through the design of non-rotating valve tips and dual sealing.

Structural Features of High-Temperature and High-Pressure Needle Valve

Adopts a hexagonal valve body structure, equipped with a non-rotating valve tip and an isolated valve stem thread lubrication system.

The valve stem uses flexible graphite packing to enhance sealing durability.

Features a dual-adjustment structure, including a top adjusting screw and a bottom V-shaped slide plate mechanical linkage device, realizing dual sealing control through a push rod spring.

An annular heat sink is added to the packing box seat, effectively reducing the valve body temperature under high-temperature working conditions.

Technical Parameters of High-Temperature and High-Pressure Needle Valve

Needle Valves for Harsh Working Conditions (DN06～15)

Application: Suitable for high-temperature, high-pressure, and frequent on-off occasions; applicable to corrosive gases and liquids compatible with the valve material.

Structure Type: Transmission threads are outside the packing, providing good high-temperature resistance and pollution resistance.

Valve Stem Sealing: Dual protection with packing seal and fluororubber O-ring seal.

Valve Core Structure: Non-rotating valve core made of super-hard alloy, with long service life.

Valve Body Material: Medium-contacting parts are made of 316L stainless steel.

Packing Seal: Graphite-reinforced PTFE for standard type; graphite for high-temperature type.

Operating Temperature: -30℃～+200℃ (standard type); -40℃～+649℃ (high-temperature type).

Maximum Operating Pressure: 500 bar for standard type (see the table below for details); 350 bar for high-temperature type.

Application Fields of High-Temperature and High-Pressure Needle Valve

The high-temperature and high-pressure needle valve has been widely used in thermal power plants, electric power, electrical engineering, mechanical and electrical equipment engineering, and electric control equipment engineering. With advantages such as easy installation, reasonable manufacturing, cost-effectiveness, and simplicity, it is extensively used as a shut-off mechanism in high-pressure high-temperature pipelines (e.g., steam pipelines) in power engineering and other pipeline systems.

It is suitable for use as an on-off mechanism in high-pressure high-temperature pipelines (e.g., primary and secondary steam valves of thermal power plants) and high-temperature chemical pipelines. The valve body is made of forged carbon steel, stainless steel (1Cr18Ni9Ti), or heat-resistant alloy steel, and the sealing surface is formed by hard alloy surfacing welding.