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A friend of mine that doesn't use the internet much runs a commercial laundry. They use an old 'Manlove Tullis' laundry calendar (c. 1980) that looks like this:

(click to enlarge photos)

Essentially, it is a machine with 3 rollers (2 visible in the photo) on a hot plate. Garments (e.g. bedsheets) go in wet, and come out ironed flat, and dry.

The hot bed runs on steam fed by 6 pipes (2 for each roller) underneath the machine, coming from a big boiler.

A couple of days ago 1 of the pipes broke off/burst under the machine with wear & tear over the years; where the pipe is joined by a coupling to the hot bed.

It is possible that over the years with repeated super-heating and cooling some metal fatigue has crept in, or it became so brittle that it finally failed.

After allowing the machine and the pipes to cool down for a day, he went under the machine to try to fix it; but the pipe is seized to the [possibly brass] coupling. The coupling affixes to the hot bed and it appears it cannot be removed because it is both seized and in an inaccessible part of the machine. It is a 22mm coupling.

The pipe is steel, and could be cut off and a new one joined by welding it or something.

Underneath the machine, the working area is only 50cm in height at most, and it is 10ft x 15ft / 3m x 5m.

From how it's been explained to me, when you're under the machine lying on the floor; the actual pipe/coupling that needs removing is within a small cavity above you. Something like this:

The space is very limited and the angle very awkward; there are also some health & safety issues with operating a welding torch under there.

An additional coupling could be added, but this introduces another mode of failure.

He has just installed a copper stop end, temporarily, so that he can use the machine with 2 out of 3 rollers operating at 100% and 1 operating at 50%.

The boiler operates at 8 Bar / 115 PSI — therefore the laundry calendar also operates at 115 PSI. From reading online I understand that the pipework is more than adequate. It is also regularly inspected and serviced.

My question is:

How can we get this pipe and/or coupling off and a new one on?

The person I'm posting this question for is very knowledgeable on the subject, but for the first time I've seen, he's stuck here. Three engineers have been out on-site and don't know what to do.

One has said that "it either needs to be welded or a proper coupling added; but it cannot be cut off because it is inaccessible".

Air
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Danny Beckett
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2 Answers2

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The way of removing couplings in the worst case scenario, where all other alternatives has failed, is to physically destroy the coupling.

Cut/grind 2 slots the entire length of the coupling on opposite sides, usually one on top and one on the bottom. The slots need to be deep enough that it is at least flush with the pipe its screwed onto, pretty much as close to the threads as possible. The closer it is to the threads the easier this will be.

Fill the top slot with anti-seize or some good EP lubricant. Get a sharp steel wedge (also covered with anti-seize) and hammer it into the slot, work slowly from one end of the slot.

If the coupling is cast iron it will likely crack right off. If its mild steel or some other soft material it will slowly open up, and you can probably unscrew it after it loosens up only a bit.

For the steel wedge, grinding down a cold chisel can work too, just taper the chisel a bit more to make it easier to hammer into the cut groove.

The anti seize prevents the steel wedge from galling against the coupling.

The cut opposite the split cut is to give the coupling a place to bend.

Netduke
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This doesn't answer the "how can we get the coupling off" question, but explores the welding option further. It seems that welding looks like one of the main options if the coupling is seized in place.

Due to the space restrictions it might be worth looking into hiring a portable orbital welding unit. This assumes that there is a pipe stub coming out of the seized coupling that could be prepared and welded to. The orbital welders are able to be used in tight spaces without much clearance behind; however, they do require careful setting of parameters.

Im not saying this is a definite solution, but it's worth looking into and possibly contacting welding unit manufacturers about parameters needed and whether it would be suitable for your application.

switchtizzer
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