Nabic 542 Safety Valve

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Mike Cole
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Nabic 542 Safety Valve

Post by Mike Cole » Tue Feb 28, 2017 6:29 pm

Have anybody used the Nabic 542 Safety Valve. I could use a new safety and buying online at http://www.nabicvalvesonline.co.uk/ priced at £113 plus VAT looks my best bet so far.

This is 3/4 bsp size. Before i order one any other valves or places I should be looking at , UK based.
Mike Cole
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Re: Nabic 542 Safety Valve

Post by steamboatjack » Wed Mar 01, 2017 9:20 am

Mike
The 542 is a standard lift valve, at 0.75 nominal size it can release 384/393 kg/hr at 150 P.S.I. I believe your boiler is fairly small. My personal choice would be to bush down to a 0.5 inch fig.500 series valve, this is a high lift version although they look identical. This has a capacity of 546/559 kg/hr. at 150 P.S.I. The high lift ones do go off with a bit of a surprise which some of our older members frown upon. Either is suitable. But I would advise running this past your boiler inspector first.

An alternative is the Bailey Burkett 707 series. I would contact Johnson Valves of Southampton, address in SBA suppliers list.
Regards Jack
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PeteThePen1
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Re: Nabic 542 Safety Valve

Post by PeteThePen1 » Thu Mar 02, 2017 11:57 am

Hi Mike

Go with Jack's advice as you will not get better. However, you might like to check Yellow Pages/Google for a local branch of BSS. They stock or will get safety valves and, being reasonably local, can be visited and questioned which is better than buying on-line. They also stock or can get a range of other steam related stuff. I suspect the downside is that they may not be the cheapest source.

Regards

Pete
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Re: Nabic 542 Safety Valve

Post by Lopez Mike » Sun Mar 05, 2017 3:47 am

I've had a safety valve that was oversized and it was not a great idea. The effects of dumping that much steam at a time are worth thinking about.
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Re: Nabic 542 Safety Valve

Post by TahoeSteam » Sun Mar 05, 2017 7:51 am

Wasn't there a discussion regarding that a few years ago?
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