In my project our subcontractor are using domestic LPG cylinder for heating the pipe during coating. In that cylinder I did not recognizing the flash back arrestor, I would like to know that the domestic regulator which is installed in domestic LPG cylinder is itself a flash back arrestor or not. meanwhile I had suggested to management to replace the domestic cylinder with industrial cylinder along with flashback arrestor. experienced suggestion is required

Is there such a thing as a 'domestic LPG cylinder'? Or do you mean that an LPG cylinder that is 'normally' used in a domestic situation is now being used in a work situation?

I work in safety and training in the compressed gas industry so in answer to your questions: Firstly there is no need for a flashback arrestor in single LPG use on heaters, torches etc. Only when the LPG or acetylene is used with oxygen. Secondly there is no difference in domestic and industrial LPG cylinders. BOC for example supply propane (the red cylinders) in cylinder sizes ranging from 4.7kg cylinders which are around 40cm high. These are commonly used for small tasks like roofing repairs. The largest cylinder we supply is E size which is around 125cm high. These are commonly used in industry but are also very common in residential caravans and in homes for supplying gas ovens and hobs where there is no mains gas supply. So no difference between industrial and domestic cylinders. You will sometimes see firbreglass cylinders in B&Q and the like sold as patio or barbecue gas. These are intended for domestic use and would not normally be seen in industry. In terms of safety, inspecting the hose for cracks or perishing, particularly at the torch and cylinder connections is very important.

Thanks to all for giving valuable information