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Flexible Hose - Tight Spacing - Decent amount of movement

Flexible Hose - Tight Spacing - Decent amount of movement

Flexible Hose - Tight Spacing - Decent amount of movement

(OP)
Hello!

First time posting.

I have a 6" ( 160 mm OD) FRP gravity flow line that needs to connect to a 6" ( 164.8 mm OD) FRP branch from a 350 MM size FRP header. According to our stress engineers, this header is going to be moving roughly 65mm laterally.

The spacing between the tip of the top pipe and the tip of the bottom pipe are unfortunately only 700 mm apart. TO make matters worse, since this header is meant to be a drain collection, the header is sloped, so there are sections of the pipe where a flex hose is supposed to fit in only about 400 mm spacing.

The size of the 6" (160 mm / 164.8 mm) OD are supposedly being driven by flow requirements. I'm checking with our engineer to make sure he needs that flow... I would like to see if I can reduce the size of the line to say DN 50, so that I can maybe fit a flexible hose that can fit this application.

The drain line, like I said, is gravity flow. There is no pressure in the line, at least not enough to warrant B31.3 construction. The idea to connect the flexible hoses is to basically get a hose clamp and tie it down.

The flexible hose needs to be a teflon type flexible hose for the commodity in the piping system.

Another unfortunate part is this gravity flow line but be sealed, because there's potential for vapor gases.   

Unfortunately the header has been fabricated, and the foundations are poured. So trying to lower the header piping is going to be a very costly decision, which is something I'm trying to avoid.

Is there such a thing as a rubber ( assuming material compatibility) boot that can handle > 2" movement that can fit over pipe? Somewhat like an accordian looking piece that can be short but can allow a lot of lateral movement?

There probably is some information I'm leaving out, so my apologies for that.

RE: Flexible Hose - Tight Spacing - Decent amount of movement

Probably not in teflon.

Go to a marine parts store and ask for a silicone 'hump hose' for 6" od exhaust tubing.  There are a couple of reputable brands, made of multiple layers of silicone rubber and reinforced with some sort of fabric.

Silicone has moderate chemical resistance and outstanding temperature resistance.  It may or may not resist your process fluid.  You can check that before going.

Silicone does not have particularly good cut resistance.
While you are at the marine parts store, ask for the full coverage/ full circle hose clamps that are appropriate for silicone hose in the size they just sold you.  Use two clamps per end.  Lubricate the clamp threads with anti-seize and tighten to 50 IN-LB, no more.

Bring your wallet.

 

Mike Halloran
Pembroke Pines, FL, USA

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