Скачать или смотреть Criticality of Gasketed Joint in a Hi-Hi Screw Plug Heat Exchanger

#ScrewPlugHeatExchanger #GasketedJoint

A highly critical gasket has to be tailored for a particular application; the shell and tube-sheet joint.

This gasketed joint in a Hi-Hi construction, with the tube-side pressure being higher than the shell-side pressure, is not so critical as the net pressure is from the tube-side.

This pressure works with the bolts, not against them, since, being directly on the gasket, it is automatically distributed uniformly.

However, when the shell side pressure is in excess of the tube side pressure, this joint becomes highly critical, as the pressure works against the bolts. These bolts transmit their load via the internal cylinder to the gasket. This load on the gasket has to be uniform.

This condition imposes several challenges, such as:

1 To achieve the highest levels of leak-proofing, the use of a kamprofile gasket demands accuracy in the manufacture of the gasket, the gasket face and the uniform bolt-tightening procedures

2 These gaskets must be especially designed for the specific joint that has to be leak proof as per EU standards.


To ensure this:

1 The hardness of the gasket-face after stress-relieving and machining must be checked throughout the gasket face.

2 After fabrication, the gasket has to be heat-treated to achieve the hardness 10 to 15% lower than the gasket face it is tailored for.

3 Tightening procedures should be such, as to apply load uniformly distributed throughout the gasket. It must be borne in mind that it’s not the torque applied, but the axial load on the gasket at each bolt location which must be the same.

4 When equal torque is applied on all bolts, the axial load of the bolts on the gasket is far from uniform. The applied torque may be consumed by the frictional losses by up to 70%. These frictional losses may not be the same for each and every bolt, hence the axial load on the gasket at each location may not be the same. Therefore, an extensive procedure is adopted to ensure uniform distribution of load.

In a nutshell, the first and foremost requirement of this procedure is to have a specially designed and manufactured gasket.


Haresh Sippy, Chairman, CMD & Chief Founder of Tema India Ltd is an engineering graduate with more than 40 years of experience in the field of Shell & Tube Heat Exchangers; he has pioneered the technology of rolling Titanium Tubes at the invitation of BAPCO, a large size refinery in Bahrain.

Follow him on twitter to know more:   / hareshsippy  

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He has developed the proprietary technology on the threaded closure of the Screw Plug Exchanger which is patented.

He was the first to develop a software and used it to do thermal design + mechanical design + fabrication drawings in a PC.


Video edited by: Tushar More