Teflon shim (washer) between 2

[sarayba]

Hello everybody,
Do I need teflon pads between the legs of the heat exchanger and concrete / steel. What is the practice? Do some standard covers? Thanks

 

[ripaldee]

Do you mean slide bearing support?

Yes, horizontal exchangers shall be fixed on one saddle and free to move in the longitudinal direction at the other saddle.

 

[Ripz]

Your sliding saddle does not always require teflon pads. They just need to have the ability to move. i.e. slotted bolt holes.

Not sure if TEMA has any guidelines, but all of our exchangers are just resting on the metal supports.

 

[sarayba]

ripaklee, thank you. However I am aware about necessity for free moving of HE, but some suppliers require slide bearing support (teflon plate) between HE support foot and concrete foundation. Some of them ask me to put steel plate instead of teflon. Is there any firm practice or standard? tnx.

 

[ripaldee]

API STD 660

 

[sarayba]

There is no anything about PTFE slide bearing for supporting legs in API STD660 as far as I know. Anyway - thank you.

 

[ripaldee]

The standard is clear that the Vendor shall be responsible for the design of the supports - with or without PTFE on the slide bearing saddle - and the Purchaser for the design review.

For further reading on PTFE slide plate assembly, please visit the website of Carpenter & Paterson Ltd. or similar manufacturers.

 

[MJCronin]

Good background design information here:

http://www.eng-tips.com/viewthread.cfm?qid=155638

Tom Barsh's comments and insights are particularly helpful....

MJCronin
Sr. Process Engineer
Venture Engineering & Construction

http://www.VentureEngr.com