Annual testing

chris m01

chris m01

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FullSizeRender.jpg Just thought I should mention the importance of annual testing. We tested three locos yesterday. We knew they were fine as we had run them and seen the safety valves lift when working pressure was reached but, as these locos may appear at exhibitions, we carried out the annual test as described by the 16mm society.
The two Roundhouse locos were perfect. The safety valve lifted fully at the right pressure and The pressure didn't rise one jot once they lifted despite the gas being on full. On the older Accucraft loco the safety valve again lifted at exactly the correct pressure (60psi) but the pressure continued to rise despite what appeared to be good "blowing off". We cut the gas when pressure got close to 80 and still rising. In normal running you would never of course leave the gas on full when a loco is blowing off hard but you never know when you might get distracted. The safety valve has been adjusted but we might send it to be refurbished as it only costs £9.
 
That is quite worrying as the Safety Valve should be able to cope with full blowing off even under a full Gas On situation. I would think that the Safety Valve has been gummed up in some way. Should be possible dismantle and clean up then refit and try again. The Safety Valve can be adjusted with a thin pair of tweezers. Adjust so that it will blow off at 20 PSI and adjust to working preasure from that. The preasure should not exceed the working one by more than a couple of PSI or so. If you do not feel confident to do this I suggest you invest in a new Safety Valve. Pitty I do not live closer as I could have looked at it for you. Or you could pop along to a nearby 16mm group, they should be able to boiler test and help you with any problems. Perhaps inviting you to join the 16mm Society if you are not already a member.

I used to do Boiler Testing for the Beds Group of the 16mm Association before I moved away.
JonD
 
dunnyrail said:
... Or you could pop along to a nearby 16mm group, they should be able to boiler test and help you with any problems.
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It is at times like these that a list of 16mm Association area groups that do have boiler testing facilities would be so useful, yet this information remains relatively secret. My local group (North West Wales) does not have boiler testing equipment and our nearest Association boiler testers are about 150 miles away, north of Manchester or near Gloucester.
 
Rhos Helyg Loco Works said:
It is at times like these that a list of 16mm Association area groups that do have boiler testing facilities would be so useful, yet this information remains relatively secret. My local group (North West Wales) does not have boiler testing equipment and our nearest Association boiler testers are about 150 miles away, north of Manchester or near Gloucester.
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So you're under quite a bit of pressure then.... ?

David
 
The 16mm association say anyone can do the annual test. The instructions are at http://www.16mm.org.uk/resources/loco-maintenance/ . If a problem is found (as we did) then we can go to a specialist to get it sorted. They also provide a record sheet although one thing missing from this sheet appears to be "does the safety valve hold the pressure steady at full gas when blowing?". The test instructions say you should do this and give guidance as to what is acceptable so I would have thought the result should be recorded on the record sheet. I'm sure they have their reasons and know a lot more about this than I do.

I must say it is great the the 16mm association have made this available to everyone and not just members.
 
chris m01 said:
The 16mm association say anyone can do the annual test. The instructions are at http://www.16mm.org.uk/resources/loco-maintenance/ . If a problem is found (as we did) then we can go to a specialist to get it sorted. They also provide a record sheet although one thing missing from this sheet appears to be "does the safety valve hold the pressure steady at full gas when blowing?". The test instructions say you should do this and give guidance as to what is acceptable so I would have thought the result should be recorded on the record sheet. I'm sure they have their reasons and know a lot more about this than I do.

I must say it is great the the 16mm association have made this available to everyone and not just members.
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I have been out of Boiler Testing as an official for some time but can understand why the question you relate to in italics is not mentioned for a Self Test as the Preasure Gauge should be tested to an annually approved Test Gauge thus proving this test with 16mm Test kit but not if your Gauge has not been tested (this way) and Red Lined at Blow Off Pleasure.
JonD
 
The annual steam test is always a bit of a non event for me, as it is something that I do automatically EVERY time I steam (apart from calibrate the gauge). Fill to half(ish) a glass, light up, bring it up to just shy of safety lift and check pumps and injectors, then let it blow off. It's what I was taught and it seems logical anyway.

With gauges you do need to be careful not to get them frosted or drop them, both can alter the settings. They are simple and easy to re-calibrate.
 
chris m01 said:
Just thought I should mention the importance of annual testing .....
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Thanks for the reminder Chris - it certainly seems an awful lot of people do attach great importance to this - but I wonder just exactly why.

Part of the problem may be due to some confusion over nomenclature. Few people would argue that the manufacturers original Boiler Test Certificate is perhaps the most critical piece of documentation any locomotive boiler can have as it certifies the original hydraulic test and is neccessary to get the CE stamp.

However, this annual steam test that we're talking about here results in a 'certificate of thorough examination' - which is not the same thing as a 'Boiler Test Certificate' at all.

As you say ....
chris m01 said:
The 16mm Association say anyone can do the annual test.
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.... including the boilers owner/operator and the vast majority of us do it anyway .....
G-force1 said:
The annual steam test is something that I do automatically EVERY time I steam
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What the self test proves is that after a period of storage things are still working as expected, particularly important with the Preasure Gauge as Chris found with his Accucraft Loco (1st post). So I commend this action to the House!
JonD
 
Oh! I never steam in the house Jon, 'Trousers' objects to steam oil dripping off the ceiling. :giggle:
 
dunnyrail said:
What the self test proves is that after a period of storage things are still working as expected, particularly important with the Preasure Gauge as Chris found with his Accucraft Loco (1st post). So I commend this action to the House!
JonD
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That is exactly right on two counts.
1. The Accucraft loco hadn't seen a lot of use since the Roundhouse loco arrived. It is quite probable that lack of use was the main reason the safety valve had a problem.
2. The safety valve appeared to be working fine as it would lift when pressure was reached. In normal running you would lower the gas at this point or sooner so you would not know it no longer had the required capacity. The prescribed test goes beyond normal operation but could just happen if there was a distraction at the wrong time revealed the problem.
 
Well here we are again - coming up to annual steam test day and still the contoversy continues - at least in our club it does.

All my locomotives are fully certified, tested and insured to run virtually anywhere in the country at public running and exhibition events - except not at my own club and a few others like them!

The problem is that our so called boiler inspectors will not accept the 16mm Associations 'Certificate of Annual Inspection and Steam Test' as refered to in 'chris m01's post #7 above.

Of course one possibility is to adopt Tag Gorton's (ex-Editor of 'Garden Rail' magazine) solution in his excellent post #14 in the thread ....

https://www.gscalecentral.net/threads/new-boiler-testing-rules.257708/

where he says ....

"Of course it will affect some people. If you are also a member of a model engineering club then you will have to consider your position. Personally I can no longer recommend that 16mm, G scale and Gauge 1 modellers join their local model engineering club."

However - I don't want to leave our club - so it occurs to me that an alternative course of action might be to question the authority of a couple of our so called 'inspectors'.

Just what are the neccessary qualifications to be an 'inspector'? - is it actually fully defined anywhere? - or can they just appoint themselves on a whim?
 
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I test all my live steamers every time I run them, which is, I have to admit, quite often. I've also marked each pressure gauge where they actually blow off. Mr Duffy of Chuffed2bits set up both safeties on my NG/G16 when it was in his care last Fall, and having run it about eight times since then it is still the same as it was back then. The habit I got into with my Gauge 1 locos, of lifting the valve with a pair of long-nosed pliers to check the function, is something I do all the time.

Incidentally, all the loose talk about boiler explosions in small-scale boilers like ours is pure horse feathers. Neither the volume of our teeny boilers nor their low operating pressures are sufficient to cause an explosion. From first-paw experience, I can confide in you all that if and when a boiler, intended to operate at 40 psi, 'lets go', it does so with a loud hiss. As the excess pressure has immediately dropped, and the volume of steam drastically reduced, the risk of a catastrophic failure is nil. The boiler that DID let go was not mine, and had actually gone off a scale set at 250 psi when a fitting leaked. The boiler itself remained undamaged, but was never used again.

tac
 
Way to many "chicken littles" and such in these societies. Glad this hasn't moved to my side of the pond. We run several scratch built gauge one/16mm engines on our portable layout. I also "test" everytime I raise steam in any of my engines. making sure the safety lifts at the correct pressure, if not, I tweak the safety with a pair of long nose plyers to see if its stuck, then make sure it lifts properly as pressure comes back up again. If not, the fire is put out and the engine set aside to be looked at once cooled down. So far, I have never had to set one aside and a quick tweak of the safety while steam is first being raised is just part of my routine after oiling round the value motion. One of my engines is scratch built by the G1MRA contact person here in the USA with a JVR type C boiler for alcohol firing and my wife's old Hyde Out Mountain Shay has a pot boiler, and was built by a gentleman in Ohio with around 100 of them being made, so almost a scratch built engine. Only my RH Billy has a true certificate from the manufacture for the boiler. I have greater concerns of a child or even an adult putting thier hand on or touching a hot engine and getting a burn, over one of the boilers letting go. When we see a parent or child getting a bit to close to the engines, we explain that the engine is as hot as the burner on the stove. That usually takes care of the "getting to close" issue. Mike the Aspie
 
I think it important to remember that with much "Self Testing" one is very reliant on the Preasure Gauge being accurate. So in spite of all the chat on here I still think it wise to have a fully authenticated Test every few years to at least prove said Gauge. Probably also worth mentioning that with the burner full on the Loco should be blowing off continuously. If it is not then the Safety Valve could be out of sync with the recommended boiler preasure.
 
dunnyrail said:
I think it important to remember that with much "Self Testing" one is very reliant on the Preasure Gauge being accurate. So in spite of all the chat on here I still think it wise to have a fully authenticated Test every few years to at least prove said Gauge. Probably also worth mentioning that with the burner full on the Loco should be blowing off continuously. If it is not then the Safety Valve could be out of sync with the recommended boiler preasure.
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Don't worry too much. As long as the safety valve is releasing steam, nothing exciting is going to happen even if above normal pressure. The next thing likely to fail would be the pressure gauge itself. As Tac says the boiler is never going to fail, even at 10 times normal or in excess of 400 psi.
Test experiment in Australia: http://www.homemodelenginemachinist.com/attachment.php?attachmentid=43409&d=1342623685
Annual test is a ok if you don't use your locos very much and I have occassionally swapped gauges between locos just to confirm they all read approx the same, I don't know what the declared accuracy of these things is, but if you have ever opened one up, you might be surprised how crude it is.
I have 20 year old Roundhouse locos produced long before the days anyone considered boiler certificates relevant and they still work well and are in constant use. There are many items in daily use greater than 3 bar/litres such as rubber tyres, aerosol cans etc, all made less substantially than a silver soldered copper boiler. I can't see that testing a boiler at 1.5 times normal, ie for Roundhouse, at 60 psi rather than 40 psi is going to prove anything or be of any use to anyone. In the case of your accucraft at 80psi, I would suggest you replace the safety valve as it lifts at 40psi but continues to rise, it is probably gummed up a bit.
 

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