In the installation of gas pipelines, it is common to use connectors for connection. Among them, VCR connector connection and sleeve connection are very common. What are the differences between the two?

Working principle

1. Working principle of VCR connector

VCR connector is a type of face seal fitting, which uses precision manufactured metal gaskets as sealing elements and has high-purity metal to metal sealing, providing leak free service in the vacuum to positive pressure range. By interlocking the internal and external threads, the flanges on both sides are pressed against the metal gasket, causing a certain deformation of the gasket and achieving a sealing effect.

2. Working principle of card sleeve connector

The working principle of the sleeve joint is to insert the steel pipe into the sleeve, use the sleeve nut and front sleeve for main sealing, and use the hinge clamping effect of the rear sleeve to form a strong grip on the tube. It does not require welding when connected to steel pipes, which is beneficial for fire prevention, explosion prevention, and high-altitude operations, and can eliminate the drawbacks caused by careless welding. Therefore, it is a relatively advanced connecting component in the pipeline of automatic control devices in refining, chemical, petroleum, natural gas, food, pharmaceutical, instrumentation and other systems. Suitable for connecting pipelines for media such as oil, gas, and water.

Joint characteristics

1. VCR connector features

VCR connectors have high cleanliness (components undergo processes such as electropolishing and cleaning) and good sealing, making them particularly suitable for ultra-high purity systems, ultra-high vacuum systems, and high-pressure systems that require no leakage. Due to the use of metal sealing components, the rated operating temperature range of VCR joints is relatively wide (VCR joints with SUS316L gaskets can reach a temperature rating of 537 ℃). The VCR connector is easy to install and has minimal disassembly clearance, allowing for repeated disassembly (reinstallation after disassembly requires replacement of new gaskets).

Welding is required between the gland of the VCR connector and the TUBE tube. VCR fittings - generally used in conjunction with automatic welding joints. Use automatic welding fittings in areas that do not require disassembly, and use VCR fittings in areas that require disassembly, such as valves and equipment interfaces. Therefore, many manufacturers combine VCR fittings (metal face sealed fittings) and automatic welding fittings on their samples, and some manufacturers also refer to these two types of fittings as Clean Fitings.

2. Characteristics of card sleeve connector

The card sleeve connector has the characteristics of reliable connection, high pressure resistance, temperature resistance, good sealing and repeatability, easy installation and maintenance, and safe and reliable operation.

Other differences

In terms of VCR connector material, the material of the gland, body, and nut is generally SUS316 or SUS316L. The material of gaskets is generally SUS316L nickel or copper (copper gaskets are rarely used now), and gaskets are divided into silver plated and non plated types. The internal thread of the VCR Female Nut is silver plated to prevent wear.

The sleeve type pipe joint consists of three parts: the joint body, the sleeve (front and rear sleeves), and the nut. The dual sleeve design separates the sealing function from the gripping function of the tube, does not transmit torque to the tube during installation, can completely replace imported tube fittings, and is fully compatible. It is easy to install and has high pressure resistance, making it widely used.

The above overview is a brief introduction to the difference between VCR connector connection and sleeve connection in gas pipeline installation!