Comparison of Various Coupling Types for Vacuum Insulated Pipe

In order to meet different user needs and solutions, various coupling/connection types are produced in the design of vacuum insulated/jacketed pipe.

Before discuss the coupling/connection, there are two situations must be distinguished,

1. The end of the vacuum insulated piping system is connected to other devices, such as the storage tank and equipment,

A. Weld Coupling

B. Flange Coupling

C. V-band Clamp Coupling

D. Bayonet Coupling

E. Threaded Coupling

2. As the vacuum insulated piping system has a long length, it cannot be produced and transported as a whole. Therefore, there are also couplings between vacuum insulated pipes.

A. Welded Coupling (Filling Perlite into the Insulated Sleeve)

B. Welded Coupling (Vacuum pump-out the Insulated Sleeve)

C. Vacuum Bayonet Coupling with Flanges

D. Vacuum Bayonet Coupling with V-band Clamps

The following contents is about the couplings in second situation.

Welded Connection Type

The on-site connection type of the Vacuum Insulated Pipes are welded connection. After confirming the weld point with NDT, install the Insulation Sleeve and fill the Sleeve with pearlite for insulation treatment. (The Sleeve here can also be vacuumed, or both vacuumed and filled with perlite. The appearance of Sleeve will be a little different. Mainly recommended Sleeve filled with perlite.)

There are several product series for welded connection type of Vacuum Insulated Pipe. One is suitable for MAWP below 16bar, one is from 16bar to 40bar, one is from 40bar to 64bar, and the last one is for liquid hydrogen and helium service (-270℃).

Pipe1
Pipe2

Vacuum Bayonet Connection Type With Flanges

Insert the Vacuum Male Extension Pipe into the Vacuum Female Extension Pipe and secure it with a flange.

There are three product series for vacuum bayonet connection type (with flange) of Vacuum Insulated Pipe. One is suitable for the MAWP below 8bar, one is for the MAWP below 16bar, and the last one is below 25bar.

Pipe3 Pipe4

Vacuum Bayonet Connection Type With V-band Clamps

Insert the Vacuum Male Extension Pipe into the Vacuum Female Extension Pipe and secure it with a v-band clamp. This is a kind of rapid installation, applicable to VI Piping with low pressure and small pipe diameter.

At present, this connection type can only be used when the MAWP is less than 8bar and the inner pipe diameter is not larger than DN25 (1').

Pipe5 Pipe6


Post time: May-11-2022