SPECIFICATION FOR SEAMLESS STEEL …

1 SPECIFICATION FOR SEAMLESS STEELTRANSPORTABLE PRESSURERECEPTACLES DOT - 3E (HSE) 1 DOT 3E (HSE) Issue 1 FEBRUARY 2000 HSEH ealth & OF OF RELIEF CYCLING BURST CYLINDERS122 DOT 3E (HSE) Issue 1 FEBRUARY 2000 INSPECTION AND TESTING13 APPENDIX 1 - INSPECTORS REPORT143 DOT 3E (HSE) Issue 1 FEBRUARY SPECIFICATION details the requirements for the material, design, construction and testing ofseamless STEEL transportable pressure receptacles, ie gas cylinders, over kg with an outsidediameter not exceeding mm, a length less than 610 mm and a service pressure of 125 cylinders to this SPECIFICATION shall not be used for the carriage of OF COMPLIANCEThe Approved Verification (Inspection) Body shall certify that the manufacture, inspection andtesting of the cylinders was carried out in compliance with the requirements of this.

2 A suitable form of certificate is shown in Appendix - Compressed Gas Association - Hydrostatic STEELOpen-hearth or electric STEEL of uniform quality. The content percentage may not exceed thefollowing OF MATERIALThe material of construction shall be identified by a suitable method and plates and billets forhot-drawn cylinders shall be marked with the heat 3E (HSE) Issue 1 FEBRUARY with seams, cracks, laminations, or other injurious defects, are not must be manufactured using equipment and processes adequate to ensure thateach cylinder produced conforms to the requirements of this SPECIFICATION . No fissure or otherdefect is permitted that is likely to weaken the finished cylinder appreciably.

3 A reasonablysmooth and uniform surface finish is required. If not originally free from such defects, the surfacemay be machined or otherwise treated to eliminate these defects. Dirt and scale shall be removedas necessary to afford proper inspection. thickness of the bottoms of cylinders welded or formed by spinning is, under nocondition, to be less than two times the minimum wall thickness of the cylindrical shell; suchbottom thicknesses to be measured within an area bounded by a line representing the points ofcontact between the cylinder and floor when the cylinder is in a vertical Welding or brazing for any purpose whatsoever is not permitted on these cylinders, exceptfor spun cylinders whose end closures are welded by the spinning thickness of each cylinder shall conform to the The wall stress may not exceed of wall thickness shall be by the following formula.

4 S = [ P/10 ( + ) ] / (D2 - d2)where S = wall stress in Mpa5 DOT 3E (HSE) Issue 1 FEBRUARY 2000P = minimum test pressure prescribed for water jacket test in barD = outside diameter in mmd = inside diameter in completed cylinders must be uniformly and properly heat treated to a procedureagreed with the Approved Verification Body prior to tests . threads are required to be clean cut, even, without cutting tool marks and to threads, when used, are to be of length not less than as specified for AmericanStandard taper pipe threads having at least 4 engaged threads are permitted and shall have a tight calculated shear strength shall be at least 10 times the test pressure of the cylinder.

5 Gaskets,adequate to prevent leakage, are RELIEF General RequirementsNo pressure relief device shall be fitted to a cylinder intended for the conveyance of toxic , a pressure relief device may be fitted to a cylinder intended for the conveyance ofnon-toxic materials of construction for all pressure relief devices shall be compatible with the gas to beconveyed and other service 3E (HSE) Issue 1 FEBRUARY 2000 All pressure relief devices shall be so designed and fitted as to ensure that the cooling effect ofthe contents of the container during discharge shall not prevent the effective operation of outlets from all pressure relief devices shall be so sited that free discharge from the devices isnot outlets from all pressure relief devices shall be so designed and constructed as to prevent thecollection of moisture or other foreign matter that could adversely affect the performance of pressure Relief ValvesIf a pressure relief valve is fitted to a

6 Cylinder, it shall be of the spring-loaded type. Wherepracticable the pressure at which the relief valve is designed to start lifting shall be marked on therelief valve or the outlet valve body where the relief valve forms part of the outlet from the pressure relief valve shall be obtained at a pressure not greater than the testpressure of the cylinder, except in the case of liquefied petroleum gas cylinders for service inGreat liquefied petroleum gas cylinders for service in Great Britain are fitted with pressure reliefvalves they shall be set as follows:(a) Propane: 26 bar.

7 (b) Butane: 21 Bursting discsBursting discs if fitted, shall be constructed in accordance with BS 2915 and shall be so designedas to ensure that rupture occurs at a pressure not greater than the test pressure of the cylinder,except in the case of cylinders for halons and 3E (HSE) Issue 1 FEBRUARY 2000 Note: A bursting disc may be fitted to any cylinder intended for the conveyance of non-toxic andnon-flammable gases. The pressure at which the the bursting disc is designed to rupture shall,where practicable, be stamped on the bursting disc a cylinder is liable to be subjected to vacuum conditions during service, the bursting disc shallbe resistant to vacuum or be fitted with a vacuum Cylinder valve protection.

8 Cylinders charged with flammable, corrosive, or noxious gases, shall have their valves protectedby one of the following By equipping the cylinders with securely attached metal caps, protective collars,neckrings or valve blocks of sufficient strength to protect the valves from damage during By boxing or crating the cylinders so as to give proper protection to the valves. By so constructing the cylinders that the valve is recessed into the cylinder or otherwiseprotected so that it will not be subjected to a blow when the cylinder is dropped on a flat By loading the cylinders compactly in an upright position and securely bracing in cars ormotor vehicles, when loaded by the consignor and to be unloaded by the By equipping with valves strong enough to avoid damage during transit for cylinderscontaining non-liquefied gas under pressure not exceeding bar at 21oC.

9 8 DOT 3E (HSE) Issue 1 FEBRUARY cylinders shall be hydrostatically tested. The hydrostatic test shall be carried out usingsuitable methods, see CGA-C-1, and operated so as to obtain accurate data. pressure gaugesmust permit reading to an accuracy of 1 percent and calibrated expansion gauges to an accuracyof either 1 percent or must be maintained for at least 30 seconds and sufficiently longer to ensurecomplete expansion. cylinder must be tested to at least 210 bar and not exceeding 315 bar and show tested to a pressure in excess of 250 bar must burst at a pressure greater than528 bar when tested in accordance with Section CYCLING cycling tests must be performed for each new design on three cylinders.

10 Thecylinders shall carry stamp marking in accordance with Section 18. The test shall be carried outusing a non-corrosive pressurising fluid. The maximum pressure in the cycle shall either be thedesign test pressure of the cylinder, or 67% of this value. The minimum test pressure in the cycleshall not exceed 10% of the maximum pressure . The frequency of cycling shall not exceed 15cycles/minute, and the temperature measured on the outside of the cylinder during the test shallnot exceed values for the test are:-12,000 cycles without failure when the maximum cycle pressure is thedesign pressure ; or,-80,000 cycles without failure when the maximum cycle pressure is 67% ofthe design test pressure .