"Boiler Regs Changed"

[Laurie_B]

In the editorial of the latest Model Engineer (Vol 198.No.4296:30 March-12 April 2007),there appears a note under the heading "Boiler Regs Changed".It goes on to say that......

"following a number of problems,mainly with testing small boilers,revisions have been made to the code for The Examination & Testing of Miniature Steam Boilers (New Edition 2006)."

I was wondering what these changes might be,and whether anyone has any more relevant information about this?

[greasemonkey]

As I understand it and I may be wrong.
Small boilers (i.e boilers with a capacity of not more than 3.0 bar-litres) are exempted from the requirements of this code. However, it is recommended that small boilers be fitted with, at least, a safety valve and a pressure gauge and that these be tested every 12 months in order to ensure correct operation at the correct release pressure.
and
On boilers of less than 10 bar-litre capacity with a total internal volume not exceeding two (2) litres it is acknowledged that the provision of two independent means of water feed arrangement may not be possible. Therefore for the purpose of testing of these boilers One (1) means of water feed arrangement is acceptable. Water in the gauge glass must recover its level without delay following movement of the boiler. Water gauges fitted to boats whose boilers fall within this size category do not have to be capable of being blown down. The water gauge and pressure gauge should be clearly visible. However your club still has the right to define its own requirements, so ask your boiler inspectors as they may not agree with the above.
Andy

[gwrfan]

Hi Laurie and others,

I quote below, the full amendment to the Boiler Regs, as sent to me by the Southern Federation. Couldn't quite get the text layout right on here (I copied and pasted from Word!). However, I hope it will help you and others:

"Revision to Boiler Test Code With Regard to Small Boilers

Introduction. Page 3, paragraph 4. Delete existing paragraph and replace with:

Small boilers (i.e boilers with a capacity of not more than 3.0 bar-litres) are exempted from
The requirements of this code. However, it is recommended that small boilers be fitted
with, at least, a safety valve and a pressure gauge and that these be tested every 12 months
in order to ensure correct operation at the correct release pressure. The boiler and the
pipework installation should also be checked at least every 12 months.

And also:

Page 11, Section 10 Steam Test. Delete the whole section and replace with:

10. Steam Test

10.1 An examination under steam pressure shall be undertaken, a) before first placing the boiler into service, b) after every hydraulic test, and c) at intervals not exceeding fourteen months.
10.2 The boiler shall be steamed and further examinations carried out as pressure is rising and whilst the boiler is at working pressure.
10.3 Correct operation of the following items shall be verified:

· Boiler water feeding arrangements by at least two independent means (hand pump, injectors, mechanical pump. Etc.)
· Pressure gauge.
· The water gauge(s) should be blown down and the water should be seen to recover to its level without delay.
10.4 On boilers of less than 10 bar-litre capacity with a total internal volume not exceeding
Two (2) litres it is acknowledged that the provision of two independent means of water feed arrangement may not be possible. Therefore for the purpose of testing these boilers:

a) One (1) means of water feed arrangement is acceptable
b) Water in the gauge glass must recover its level without delay following movement of the boiler. Water gauges fitted to boats whose boilers fall within this size category do not have to be capable of being blown down.
c) The water gauge and pressure gauge should be clearly visible.

10.5 The boiler shall then be steamed at maximum firing rate and with full blower
operation. The test shall be continued for sufficient time as to allow the Inspector to
be satisfied that stable conditions have been attained. The operation of the safety
valves shall be checked to ensure that they operate at working pressure and that
pressure does not rise by more than 10% of the working pressure during safety valve
operation."

Geoff

[Laurie_B]

Hi Andy and Geoff,
Thankyou for the detailed replies,much appreciated.

[GWRdriver]

Am I corect to assume that "3.0 bar-litre" in the context of the regulation is a boiler which operates at 3.0 atmospheres or less, AND has a volume of 3 litres or less?

[gilesengineer]

No, three bar/litre would be 1 bar with a three litre capacity, or three bar pressure with a one litre capacity, and so forth.....

[Nigel Bennett]

H'mm. I've just had my boiler on "Tiny" tested - a 3.1/2"g 0-4-0ST. It's a bit like "Juliet" but it was built in 1946, before "Juliet" was designed. It works out at 2.67 bar litres, so less than the 3 bar litres quoted.

I can't see a problem with two independent feeds - a hand pump and an axle pump surely aren't too difficult! An injector might well be a bit fiddly and unreliable in this size, though.

I don't think I'm particularly happy with the 3 bar litre limit - I wouldn't like to be near it a-going bang!

[mackintosh]

I have just just come up to this problem with my Minnie Roller, the boiler was hydraulic tested last year passed no problems. I thought I might have to add another bush to fit a clack for another feed. The problem was finding a small reliable injector.
But having read all the reply's to this thread it seems I don't need to panic. The only problem I can see is interpretation does this mean that a hydraulic test needs to be carried out every 14 months along with the steam test or have I got it wrong

[teakfreak]

I think it is worth mentioning that with some older models it may be necessary to replace safety valves, or at least re-work the old ones, to provide steam releasing capability in line with modern requirements.

I've just bought a 3-1/2" gauge A4 built back in the 1960s to the Clarkson design and it had to have some moidifications to the safety valves in order to pass its in steam test.