Steam Testing Rules & Regulations

Transcription

1 MPBA MODEL POWER BOAT ASSOCIATION Steam Testing Rules & Regulations 1. TEST PANELS AND CERTIFICATES Model boat clubs, societies and groups of clubs that are affiliated to the M.P.B.A. and operate steam powered models, are encouraged to establish testing panels (minimum two persons, preferably three) for the purpose of testing model boilers and pressure vessels. Where clubs may find this impractical the advice of the area representatives or the General Secretary should be sought In addition to official M.P.B.A. certificates, those issued by THE NORTHERN ASSOCIATION OF MODEL ENGINEERS, THE SOUTHERN FEDERATION OF MODEL ENGINEERING SOCIETIES and other recognised bodies, including those not residual in the United Kingdom, will be acceptable, providing their test methods and standards are similar to those of the M.P.B.A Event officials should be diligent in ensuring the above is adhered to at all times. A guide, MPBA STEAM STARTER PACK is available from Keith Bragg. 6, Meadow Close, Grimoldby, Nr Louth, Lincs. LN11 8HY Which outlines the NPBA Record Keeping Systems. Numbered Test Certificates are also available for use by MPBA Affiliated Clubs. 2. TESTERS AND TESTING All testers should be deemed to have a practical working knowledge and a suitable understanding of the required theory. Testers shall not be the owners or builders of vessels under test The pressure gauge used for testing must not be a model gauge, but a reliable industrial type having a current calibration certificate M.P.B.A. affiliated clubs that carry out testing should maintain records which contain the history of tests, certificates issued, failures, address/ownership changes, calibration certificates and any other relevant documentation The M.P.B.A. or any duly appointed testers shall not be deemed liable for any damages to boilers/pressure vessels incurred whilst in the process of testing or certification The maximum pressures that affiliated clubs and societies will be willing to test to is entirely at their discretion. Likewise their agreement to test L.P.G. fuel tanks If a boiler is deemed to have passed an inspection and pressure test, an MPBA Test Certificate can be issued. They are available only to MPBA Members and no charge is made for the certificate. Refer to the MPBA Steam Starter Pack for conditions and record keeping systems. The certificate that is issued confirms that the boiler was satisfactory on the day of the test. It has a life of MPBA/STEAM/JAN98/1

2 two years but is not a guarantee that the boiler is safe between the date of issue and the issuing of the next retest certificate. If ant changes are made to the boiler, after the date of testing, the certificate will become in validated and a retest will be necessary Current Boiler Test Certificates will need to be available for inspection at MPBA regattas. 3. COPPER BOILERS/PRESSURE VESSELS All new boilers/pressure vessels should be submitted for initial testing under these rules. Commercial units as produced that carry current test certificates will not require testing until they reach two years of age All new boilers/pressure vessels will be examined externally and, as far as possible, internally; cladding and/or fittings are to be omitted for the initial test, normally the requestor will supply boilers/pressure vessels with suitable plugs and seals for the various bushes. If problems are encountered then discussion with the testers may offer an alternative. It is recommended that discussion should take place well in advance of the required test in order that problems can be minimised. Following the fitting of the necessary blanking plugs and water feed union, the boiler/pressure vessel shall be subjected to a progressive hydraulic test. During the process of adding water to the test piece care should be exercised to ensure the expulsion of all air from the vessel space, pipework, fittings and test pump. The test piece shall be subjected to a pressure that equals a figure of twice the declared normal working pressure. Upon reaching the test pressure it shall be held for sufficient time to ensure that a thorough inspection can be executed. If any leaks or weeps occur then the test will be halted until the faults are rectified. ANY LEAK OR WEEP CONSTITUTES A FAILURE Any appreciable distortion will cause a boiler/pressure vessel to be rejected. Leaks/weeps should be marked with soft pencil or chalk or otherwise related to the requestor in order that corrective action may be carried out. A retest can then be conducted All copper boilers/pressure vessels are to be tested every two years. For renewal after the initial two year period, and any subsequent tests, the test pressure shall be to one and one half times the declared working pressure, it being applied once only. The procedure being the same as that described previously in paragraphs 3.1, 3.2, 3.3,. Second and subsequent tests will also include an examination of boiler fittings, cladding need not be removed unless specifically requested by the test panel. For reasons of safety WATER GAUGE GLASS WILL NOT BE FITTED DURING TESTING, its removal being the responsibility of the requester Any boiler/pressure vessel constructed to other than recognised published designs should be presented together with the minimum of a dimensioned sketch, thus enabling basic calculations to be made. It is strongly recommended that designers/builders enter discussions with their testing panel in the early design stages The preceding paragraphs refer to boilers/pressure vessels constructed from copper, using silver soldered or hard brazed joints and flanges. Where possible bronze should be used for the manufacture of bushes and fittings, although brass is acceptable. MPBA/STEAM/JAN98/2

3 3.7. Any structural modification or repair will require an initial test to be carried out to twice the declared working pressure. 4. BRASS BOILERS All new boilers are to be tested in accordance with the standards applied to those of copper material IT IS STRONGLY RECOMMENDED THAT BOILERS ARE NOT MANUFACTURED FROM BRASS, however for those that are, including various commercial units, then second and subsequent tests must be carried out ANNUALLY TO TWICE THE DECLARED WORKING PRESSURE. An inspection should be made for corrosion and Zinc leaching. 5. STEEL BOILERS IT IS STRONGLY RECOMMENDED THAT BOILERS ARE NOT MANUFACTURED FROM STEEL. M.P.B.A. affiliated clubs and societies are not obliged to offer testing facilities for such units. In all cases steel boilers require an annual test. 6. SAFETY VALVES A safety valve or valves must be fitted to all boilers, the lack of provision for such will mean test rejection. To ensure correct and continued operation of valves, operators of steam powered models must carry out checks for correct functioning on each occasion that steam is raised. Lift should occur within 10% of the normal declared working pressure Safety valves of the fixed rate type, i.e., non-adjustable, should be subjected to a steam test, the lift-off pressure should not exceed 10% above the normal declared working pressure. If found to be otherwise then the working pressure must be calculated to correct the differential. The new figure must be proven by test, recorded on the test certificate and endorsed by the test panel. 7. MONOTUBE BOILERS Monotube, also called Flash Steam boilers do NOT require a test certificate. 8. PRESSURISED FUEL CONTAINERS/TANKS [L.P.G.] All refillable containers/tanks used to hold gas, i.e. BUTANE OR BUTANE/PROPANE combinations used in model steam craft must be tested every two years. Their design and construction must be to the same standards as those for boilers, be made of copper and designed to have a maximum internal volume of 450cc. L.P.G. tanks of commercial origin manufactured from brass are acceptable. It is recommended that liquid gas is not stored in such tanks after use. The test pressures used must be appropriate to the gas mix that is declared as used by the operator. MPBA/STEAM/JAN98/3

4 GAS TEST PRESSURES GAS MIX % TEST PRESSURE Butane bar psig. Butane/Propane 90/ bar psig. Butane/Propane 80/ bar psig. Butane/Propane 70/ bar psig. Butane/Propane 60/ bar psig Pressure to nearest 0.5 including x1.9 safety factor 8.2. Containers/tanks must be examined and then tested hydraulically as in Section 3. Boilers. The test pressure being taken from the table above. There shall be no leakage. Following the hydraulic test the container/tank must be drained and completely dried, all valves/fittings and seals fitted and the test piece then filled with the appropriate gas. Using a container of clean water at normal room temperature, the container/tank must be fully immersed. Any evidence of leakage constitutes a failure and should be noted, if safety valve/valves are fitted there shall be no evidence of valve lift or gas escape. IT IS NOT RECOMMENDED THAT REFILLABLE GAS TANKS ARE FITTED WITH SAFETY VALVES. If such valves are fitted, then when installed in models there must be a means of piping any efflux to the exterior of that model. Units must also include a device or means whereby filling to its total capacity is prevented IT IS STRONGLY RECOMMENDED THAT THE RE-FILLING OF TANKS WITH GAS IS EXECUTED OUTDOORS, AND WELL AWAY FROM OTHER PERSONS Gas containers of the disposable type are not subject to the M.P.B.A. test requirements, although fittings manufactured by the requestor or conversions may come under scrutiny In order to show understanding of the difficulties of model installations the use of flexible hose is permitted. However, for low heat gas burners (see para.8.7.) the first 102mm. of pipe MUST be of the appropriate size of copper. For high heat gas burners the first 153mm. MUST be of copper. The remainder of the connection to the gas supply may only be of hose that meets B.S.3212 and/or 737/17. E.g., B.S.3212/2/4 08/94 where 3212 is the Standard, /2 is high pressure, /4 is bore size, and 08/94 is the date of manufacture. 737/17 is an international standard. NO OTHER TYPE OF HOSE IS PERMISSABLE. This concession applies to L.P.G. containers/burners only. All copper pipe is permissible When utilising flexible hose and copper pipe for burners, the appropriate connections must be used. Likewise the sizes of pipes and hoses, e.g., copper pipe should be smooth flared or have the correct convolute form, silver soldered on, and hoses must be clipped For the purpose of these test recommendations the definition of low/high heat burners is as follows: LOW HEAT GAS DISSIPATION THROUGH A CERAMIC MATERIAL BURNER. HIGH HEAT GAS AND AIR MIXING WITHIN A COMBUSTION TUBE RESULTING IN A SINGLE OR MULTIPLE FLAME PROJECTION. MPBA/STEAM/JAN98/4

5 8.8. All seals, O rings and gaskets should be inspected regularly by the owners/operators of all pressure vessels. With particular reference to L.P.G. tanks it is preferred that NEW seals are made available for certification tests. 9. LIQUID FUELS OTHER THAN L.P.G Containers or tanks should be examined and tested as for boilers (refer to Section 3.). The test pressure must be to twice the normal declared working figure. If this information is not given, or available to the testers, the test pressure used must then be 75psig. Re-certification is as for boilers (see Section 3.). These tanks may be constructed of brass of suitable thickness. NOTES The pressures quoted in 8.1 were derived from data supplied by commercial gas supply sources. The required calculations are in accordance with the guidelines of these companies and also with BS and BS EN. 417 (European) is also relevant. The method of calculation contained the following elements: Maximum developed saturation pressure at 55deg. c. Safety factor x 1.9. Calculations in bar. Conversion to p.s.i. - 1bar = p.s.i. Test figures rounded to 0.5 BS 5355 includes filling ratios and developed pressures of liquefiable and permanent gases, in addition it also observes maximum shade temperatures worldwide. Therefore the stated shade figures shown below should not be exceeded. COUNTRY DEGREES/C United Kingdom Germany France In the case of a change of ownership, the former and new owner should notify the area representative by completing a change of ownership form (available from club testers). Duplicate certificates required due to loss or defacement may be obtained from the original issuing panel at cost. Photocopies will be acceptable as proof of testing, provided that they are countersigned by one of the original testers. ALL BOILERS AND PRESSURE VESSELS MUST CARRY A FORM OF PERMANENT IDENTIFICATION, THE INDENTIFYING CODE AND METHOD OF MARKING TO BE AGREED WITH THE TEST PANEL AS APPROPRIATE. THE M.P.B.A. OR ITS APPOINTED TESTERS WILL NOT BE LIABLE FOR ANY MISUSE BY OWNERS OR OPERATORS OF BOILERS OR PRESSURE VESSELS. MPBA/STEAM/JAN98/5

6 MPBA Steam MODEL POWER BOAT ASSOCIATION CODE OF OPERATING PRACTICE FOR STEAM POWERED MODELS The steam committee of the MPBA recommend the following code of practice for the benefit of those either organising and/or participating in MPBA events, the main purpose being to encompass the practical operation of steam powered models and to ensure maximum safety. 1. ORGANISERS 1.1 Regatta compounds must include an area for the specific purpose of the re-filling of burner tanks, members of the public and non-steam operators to be excluded at all times. 1.2 The model operating area must include a space for the purpose of raising steam and the blowing down of boilers etc., members of the public and non-steam operators to be excluded at all times. The waters edge being the most practical sitting. 1.3 Event officials must request and be presented with valid test certificates before allowing participants to steam up. In addition to MPBA certificates, those issued by the Northern Federation of Model Engineers, the Southern Federation of Model Engineering Societies and other recognised bodies, including those not residual in the UK, will also be acceptable, provided that the test methods and standards applied are similar to those of the MPBA 2. OWNERS/OPERATORS 2.1 It is the direct responsibility of the steam plant owner/s to acquire and maintain a current certificate/s for pressure vessels contained within their model. The only exceptions being commercially available gas canisters, monotube boilers and commercial steam plants that are covered by current manufacturers test certificates It is the direct responsibility of model steam plant owners to ensure sufficient maintenance is carried out, such that the operation of the plant may take place without foreseen hazard. 2.3 It is the direct responsibility of operators to take proper precautions when refilling fuel tanks of any description. Particular attention should be paid to naked flame or any means of spark generation within the vicinity (ref. para. 1.1). 2.4 It is the direct responsibility of operators to ensure that any fuel leakage or spillage, whether liquid or gas, is dealt with immediately, particularly if within a model. 2.5 The use of 100% Propane gas is NOT permissible. 2.6 The use of heating devices for LPG (liquid petroleum gas) tanks or containers is NOT permissible. Code of Operating Practice for Steam Powered Models /1

7 3. RECOMMENDATIONS FOR USE OF PRESSURISED PETROL/PARAFFIN BLOWLAMPS. 3.1 Positive pressure to the blowlamp may only be applied by: (a) The use of a hand operated air pump. (b) The use of an external, commercially available inert compressed gas container. 3.2 Where the use of 1 (b) is to be applied, the blowlamp pressure vessel must be tested to the rules set down in section 8.1 of the MPBA Steam Testing Rules & Regulations with a recommended test pressure of 300psi 3.3 The blowlamp pressure vessel test certificate shall show petrol and/or paraffin + type of inert compressed used, and shall be valid for two years from the date of test. 3.4 Under no circumstances shall the pressure vessel be charged whilst the burner is in operation. 3.5 The use of any form of flammable / highly volatile compressed gas for pressurisation is strictly forbidden. All other MPBA rules apply