PTFE PAD IN BARE NON INSULATED LINE

Dear Experts,

In one of my projects, I came across the requirement for PTFE pad on non insulated line.

Generally all support standards call for shoe or trunion for PTFE requirements.

Can we provide PTFE without shoe or trunion welded to pipe.

Need expert advise

Hi there,

In my opinion, PTFE Pad provided for friction reduction purpose between relatively sliding parts of pipe supports should be considered for plane contact surfaces only, meaning for shoe-type (or equivalent, such as saddle or trunnion-type) attachments to the pipe components.

If you have a bare pipe sliding on the plane top-surface of the supporting structural member (with/without reinforcing pad attached to pipe and/or isolation pad fixed to top of steel), then there is a quasi-linear contact between the sliding components. You cannot count on the friction factor decrease here.

Certainly, this is my personal opinion, and I've applied it on all projects I've worked so far. Although I've met initial opposite opinions trying to make the second option acceptable, finally I've never met a documented and fully argued professional opinion to demonstrate the validity of that second case.

In all standard supports collections used by internationally recognized companies I've worked with so far, the standard supports intended to employ reduced friction factors were developed based upon plane contact surfaces (usually polished SS Plate welded on the bottom surface of pipe support attachment - shoe, saddle, trunnion sliding on he Teflon Pad bonded on the top surface of supporting structural member).

Maybe other Forum's members might have other opinions based on other criteria or circumstances.

Hi,

I will not recommend using PTFE plates for non-insulated pipes (if you don’t have a welded shoes, clamp or trunnion to go with). If you really required to use the friction effect try with Rigid Hanger (the position of pipes is not clear from your above post). But Rigid Hanger can be a good option.

Be wise while using the option of PTFE plate.

Regards,
R.K.