Black iron pipe between two fixed points?

[julianf]

This is related to that blast pot, but it's a topic in itself -

Say you have two ports on a tank, or on a wall, or whatever, and you want to put iron pipe between them, how is this achieved?

I'm thinking that even if your tails were the exact right length, you would still need some flex / play to use unions, which isn't generally available on black iron pipe.


I may not be explaining myself well...

Say you need to change a standard central heating pump. You can remove the pump by undoing the "union" connectors with the large washer and just slide out the pump perpendicular to the pipe. If it were only the compression fittings you would need to flex the pipe.

Black iron unions are akin to copper compression - they slot into each other.

How can you create a bond on iron pipe without the need to change the length of the pipe when assembling the union?


Thank you.

 

[Erie Fred]

Vitaulic

 

[DAPPH]

Have a look here for" Straight Black iron couplings " some have ground flat faces to do what you are after . the other option is use elbow couplings to make the link removable perhaps call or email them for advice

Black Malleable Iron Fittings

Black Malleable Iron Fittings

www.waterlineproducts.co.uk

 

[waddycall]

Flat face union. Or don’t worry about it as you’ll probably be able to force as normal union.

 

[mtt.tr]

As above flat face union, especially short pipe put a flexible pipe on.

Hydraulic pipe is ideal

 

[bricol]

Or flanges.

Socket weld unions would be easiest. Second would be weld nipples and unions - screw the nipples into unions, install unions, cut pipe to fit, tack in place, remove and fully weld.

 

[Bornfree]

Flat seat unions were always the way. But nowadays you can get compression fittings for every type of pipe including iron/steel.

 

[Robotstar5]

Fitters I've worked with use a coupling they call a Navy union - link

 

[Agroshield]

Fitters I've worked with use a coupling they call a Navy union - link

That is a standard taper seat union.

Unions, whether pipe or trade, are quite expensive.

Two taper seat unions might work. You'd just have to screw each piece on 1/4 - 1/2 turn extra to create the space, insert the infill piece, and then unscrew each piece to close the gap.

The other alternative (a lot cheaper) is a long screw (but being BSPP, it will need goop on it to seal):

LONGSCREWS COMPLETE BLACK Mild Steel Screwed Pipe Fitting - Pipe Dream Fittings

The Longscrews Complete Black Mild Steel Screwed Pipe Fitting is a high-quality, durable, and rust-resistant product that can be used in a variety of plumbing applications.

pipedreamfittings.com

pipedream fittings have all three products, long screw, taper seat union and flat seat union so you can compare prices.

 

[bricol]

If it wasn't identifiable, I'd throw up a view of a drawing done by a colleague with no idea of pipes, fittings or how a pipe-fitter can put stuff together. It's absolutely crazily over the top. Unions just about everywhere so elbows etc can be aligned. Even unions before and after hoses.

That, or he's got shares in a union supply company!

 

[Kayos]

When installing something you work to a fitting, instead of to a corner like you would with crimp or solder

Ground face union, flat face union, flanges, and for those of a certain age a Long Screw

 

[Kayos]

That is a standard taper seat union.

Unions, whether pipe or trade, are quite expensive.

Two taper seat unions might work. You'd just have to screw each piece on 1/4 - 1/2 turn extra to create the space, insert the infill piece, and then unscrew each piece to close the gap.

The other alternative (a lot cheaper) is a long screw (but being BSPP, it will need goop on it to seal):

LONGSCREWS COMPLETE BLACK Mild Steel Screwed Pipe Fitting - Pipe Dream Fittings

The Longscrews Complete Black Mild Steel Screwed Pipe Fitting is a high-quality, durable, and rust-resistant product that can be used in a variety of plumbing applications.

pipedreamfittings.com

pipedream fittings have all three products, long screw, taper seat union and flat seat union so you can compare prices.

The Long Screw used to be part of the ACS assessment, cheap because they are fiddly, needing both hemp and paste, and also obsolete.

Very rarely seen in the wild as a ground face union is smaller and simpler to fit

 

[Mikes]

Just use unions (can be normal cone type) in the two stubbs from the vessel. No flexing of pipe required. Drawing attached.

 

[DAPPH]

If it wasn't identifiable, I'd throw up a view of a drawing done by a colleague with no idea of pipes, fittings or how a pipe-fitter can put stuff together. It's absolutely crazily over the top. Unions just about everywhere so elbows etc can be aligned. Even unions before and after hoses.

That, or he's got shares in a union supply company!

Is he a union man then ?
As an aside in a B&B we stayed at in Quebec up in our attic room there was a massive two foo high two foot wide by four foot cast iron radiator made entirely of iron pipe elbows and unions . I've never ever seen one like it before or ever since but was grateful for it as it was the year the temp went from minus 44oC to 44.3 oC in Quebec . . Up in our atic room it may have been hotter , we were just pleased to sleep or lay right next to it for the little bit of cool respite it offered.

 

[julianf]

My next, related, question -

Making tube the right length without dedicated equipment, as the gap is unlikely to be "off the shelf"

On black iron, are both the pipe and the fitting tapered, or is one parallel and the other tapered?

 

[Mikes]

My next, related, question -

Making tube the right length without dedicated equipment, as the gap is unlikely to be "off the shelf"

On black iron, are both the pipe and the fitting tapered, or is one parallel and the other tapered?

Both are tapered threads. There are what is called 'A' dimensions for the fitting which show the allowance for the thread engagement in the fitting. If you know the centre line of the fitting to face dimension then it is easy to work out the pipe length required. I've got the 'A' dimensions if you need them. They vary for the pipe diameter so just need to know what you are using.

 

[Agroshield]

This a good, one stop reference:

https://www.gfps.com/content/dam/gfps/com/product-ranges/en/gfps-product-range-malleable-cast-iron-fittings-en.pdf