gas compression fittings

[WotEver]

This is it. The job should have been pickled afterwards or at least scrubbed with soap and water.to remove excess flux.

 

When I first started work in a factory we had to scrub the back of any pcb that we'd soldered with 'Trike' and a short bristled stiff brush. I still do it to this day (albeit not with trichloroethylene, 'cos I can't get it).

My understanding is that silver solder includes a small percentage of silver, I think to help it flow, hence the name. The resultant joint is not, however, silver coloured.

 

Perhaps there's more than one type of silver solder? Silver jewellery is silver soldered and it's most certainly silver in colour.

[RLWP]

Perhaps there's more than one type of silver solder? Silver jewellery is silver soldered and it's most certainly silver in colour.

 

There are lots of types of silver solder

 

http://www.billshorthousemetals.co.uk/products/cadmium-free-silver-solder/index.html

 

Richard

[WotEver]

 

There are lots of types of silver solder

 

http://www.billshorthousemetals.co.uk/products/cadmium-free-silver-solder/index.html

 

Richard

 

Oooh, wow... lots and lots and lots...

 

How many of them look silver once soldered?

[MtB]

 

Ah. Right. I mean testing newly installed pipework for leaks before any appliances are connected. Stick push-fit stop-ends on the tails and pressure up. You can tell from the gauge if there's a leak but I'd always spray the joints.

 

 

I'm reasonably sure from this you are not Gas Safe Registered and should not be carrying out gas work.

Let alone handing out dodgy gas advice to others.

[mross]

Some solders will join glass! And glass to metal!

[Guest]

When constructing model copper multi tubular loco boilers you go through several stages using different temperature brazes and silver solders otherwise one would keep melting the previous operation and ruining the whole job. For example, the foundation ring would be brazed first with say Sifbronze. The tube plates, fire and superheater tubes would be silver soldered with, say Easyflow No1. Firebox wrapper, stays ect with, say Easyflow No2, Fittings ect Easyflow No3.

All stages using slightly lower fusing temperatures so as not to melt the previous stage. Similar operation with vehicle radiators and heat exchangers. You would only soft solder low pressure model boilers designed work at no more than about 20psi.

This is it. The job should have been pickled afterwards or at least scrubbed with soap and water.to remove excess flux.

I am sure it was the result of poor workmanship. It was a horrible 60's concrete building, obviously thrown up in a hurry. Makes you wonder how many gas pipes have been left like this though?

[RLWP]

 

Oooh, wow... lots and lots and lots...

 

How many of them look silver once soldered?

 

Actually silver type silvery? Non of the ones I've used on copper and steel, they are usually a silvery yellow colour.

 

Richard

[nicknorman]

 

Actually silver type silvery? Non of the ones I've used on copper and steel, they are usually a silvery yellow colour.

 

Richard

I got some silver solder from ebay, a shiny silver stick but it is more of a pewter colour after use.

[ditchcrawler]

 

Ah. Right. I mean testing newly installed pipework for leaks before any appliances are connected. Stick push-fit stop-ends on the tails and pressure up. You can tell from the gauge if there's a leak but I'd always spray the joints.

How long do you leave it locked in for?

[stegra]

 

 

I'm reasonably sure from this you are not Gas Safe Registered and should not be carrying out gas work.

 

No. I first fix the pipe for the gas guy, with his approval so he only has to come out once. Normally just a new 22mm to a bigger cooker, sometimes a new location. I test the same I would for water. He tests as well of course. The push-fits are just for the test. I don't make any connections to gas or appliance.

 

Edit: I should perhaps point out that I'm talking about testing with air, not connecting the gas and going round with a tin of leak spray.

Edited January 13, 2017 by stegra

[MtB]

For

 

 

Ah. Right. I mean testing newly installed pipework for leaks before any appliances are connected. Stick push-fit stop-ends on the tails and pressure up. You can tell from the gauge if there's a leak but I'd always spray the joints.

 

 

For people reading this and thinking "oh thats a good way to do it", It isn't. It is so wrong my gob is smacked that a RGI supervising this work considers it acceptable.

 

For the avoidance of doubt the correct way to test new pipework is with air at very low pressure, typically 20mbar or 70mbar depending on which gas the pipework will be carrying. A water manometer may be used with a scale resolution of 1 mbar, or a digital manometer with scale resolution of 0.1 mbar or better. The goal is to then register a drop of zero mbar after a temperature stabilisation period of one minute.

[nicknorman]

For

 

 

 

 

For people reading this and thinking "oh thats a good way to do it", It isn't. It is so wrong my gob is smacked that a RGI supervising this work considers it acceptable.

 

For the avoidance of doubt the correct way to test new pipework is with air at very low pressure, typically 20mbar or 70mbar depending on which gas the pipework will be carrying. A water manometer may be used with a scale resolution of 1 mbar, or a digital manometer with scale resolution of 0.1 mbar or better. The goal is to then register a drop of zero mbar after a temperature stabilisation period of one minute.

 

Out of interest, could you explain why using a higher test pressure for basic pipework (no appliances connected) is a bad thing? At first sight to the uneducated, it doesn't seem a bad idea.

[MtB]

Out of interest, could you explain why using a higher test pressure for basic pipework (no appliances connected) is a bad thing? At first sight to the uneducated, it doesn't seem a bad idea.

 

 

The poor resolution of the gauges that measure high pressures I'd imagine.

 

In addition, many years ago I tried a bench experimement which rather confirms this. I created a section of pipe with a really tiny leak - one which dropped a couple of millibars of pressure from 20 mbar over about a two minute period.. (Same time as I experimented with bubble testers as it happens.)

 

I pumped it up to 2bar and it seemed to retain the pressure but was difficult to tell reading the pressure on a Bourdon gauge.

(Well may not have been two bar, but it was A LOT.)

Mind you it would probably have shown up with LDF had I thought to try it.

[nicknorman]

The poor resolution of the gauges that measure high pressures I'd imagine.

 

In addition, many years ago I tried a bench experimement which rather confirms this. I created a section of pipe with a really tiny leak - one which dropped a couple of millibars of pressure from 20 mbar over about a two minute period.. (Same time as I experimented with bubble testers as it happens.)

 

I pumped it up to 2bar and it seemed to retain the pressure but was difficult to tell reading the pressure on a Bourdon gauge.(Well may not have been two bar, but it was A LOT.)

Mind you it would probably have shown up with LDF had I thought to try it.

Ah yes I get that, on two grounds. One being the difference in "stiction" and resolution as a % of fsd between a water manometer and a bourdon gauge, and secondly that a high pressure might actually seal a leak that would leak at operational pressure. So obviously it is better to check the system under the conditions it will be used rather than under conditions it will never experience in operation. Edited January 13, 2017 by nicknorman

[Ex Brummie]

If I have a minimal leak on a gas supply pipe, I know that what fails on a 10mm pipe may well pass on a 15mm pipe.

[MtB]

If I have a minimal leak on a gas supply pipe, I know that what fails on a 10mm pipe may well pass on a 15mm pipe.

 

 

Correct. That is why one calculates system volume before looking up what test procedure to use.

[Murflynn]

It is interesting as the BSS allows ony Compression fittings whereas the current ISO std - BS EN ISO 10239:2014 allows the use of 'hard soldered and brazed connections' with a melting point greater than 450c. So I could build a boat using hard soldered connections, CE mark it for sale, sell it and then it would fail the BSS.

Looks like the BSS office is failing to stay up to date with the regs.

there is no reason why a body that sets standards for a particular area (read BSS in this case) should not select their preferred method from those permitted by the ISO. It is not incompatible to do so.

If you were the BSS man, how could you tell whether a soldered joint has a melting point >450C just by looking?

 

But anyway, as I mentioned earlier this is why the likes of MtB always ask what regulations a questioner wants to meet. The ISO is a pan European regulation, the BSS a British one and it is surely not the only area where U.K. requirements differ from European ones!

use of the word 'differing' is misleading.

 

better to use the words 'more specific'.

Welcome to the strange world of standards. There is an international standard and there is a British standard and the two happen to be the same.

What will be interesting, is that when we are no longer bound by EU directives we MIGHT end up where the ISO standard is updated, but we choose not to update the British Standard. Time will tell, but as organisations such as BS exist and survive on the basis of changing standards, then I guess that they will continue to keep updating.

not the case. British Standards were normalised with ISOs long before we subscribed to European Norms. The international market doesn't give a damn about EN. ISOs are the bible for any country wishing to export.

[Mikexx]

Some solders will join glass! And glass to metal!

 

Leaded lights usually use a copper foil wrapped around the glass edge which is then soldered.

 

I'm not aware of solders that alloy/wet with glass?

 

Can you provide any examples?

[MtB]

 

Leaded lights usually use a copper foil wrapped around the glass edge which is then soldered.

 

 

 

No not really. That is a DIY/hobby method for lamp shades etc.

 

Real leaded panes use 'H' profile lead sections to hold each shaped piece of coloured or textured glass which are soldered at the joints and whiting and linseed oil mix is then worked in to seal the finished work so it is waterproof.

 

I must make some more leaded light panels. Not made any for about 20 years but IIRC terrribly time consuming. About eight hours a square foot!

[mross]

 

Leaded lights usually use a copper foil wrapped around the glass edge which is then soldered.

 

I'm not aware of solders that alloy/wet with glass?

 

Can you provide any examples?

https://en.wikipedia.org/wiki/Solder#Glass_solder

[Mikexx]

https://en.wikipedia.org/wiki/Solder#Glass_solder

 

Thanks. I associate solder with metals and hadn't considered glass solders actually made from low melting point glass!

[mross]

Most of the solders listed are alloys of metal. Did you look at the table?

[Chewbacka]

Most of the solders listed are alloys of metal. Did you look at the table?

Not for soldering to glass. Though glass and glass ceramics are made out of oxides of metal atoms, such as silicon, Aluminium etc. Lead crystal glass contains lots of lead, but I wouldn't describe it as a lead alloy.

[mross]

Yes, for soldering glass! Indium-Tin, Tin-Antimony, Tin-Copper-Silver, Indium-Silver are all used in soldering glass. On the link I quoted, are over 50 mentions of glass.

[Chewbacka]

Yes, for soldering glass! Indium-Tin, Tin-Antimony, Tin-Copper-Silver, Indium-Silver are all used in soldering glass. On the link I quoted, are over 50 mentions of glass.

You are correct, I forgot that Indium alloys are good for soldering to glass. I actually worked in a plant that did just that, though it was about 40 years ago.