How to choose a cutting torch R1 and R3 in appearance - Завод автогенного оборудования ДОНМЕТ производит газосварочные горелки, газовые резаки, керосинорезы, редукторы и другое сварочное оборудование
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News Cutting and welding of metal in theory How to choose a cutting torch R1 and R3 in appearance
How to choose a cutting torch R1 and R3 in appearance PDF Print
Tuesday, 28 December 2010 14:39

I. First of all take a cutting torch in your hand! You can not make a choice just looking at the picture, advertisement or just based on the price.

II. You have to decide! What application are you going to do?

For example: If you need to cut metal thickness up to 100 mm, in this way the best choice for you would be cutting torch type R1 (hose Ø6 mm), And if the metal thickness to be cut is more than 100 mm (up to 300 mm), choose a cutting torch type R3.

Choose the type of available gas (propane, acetylene, methane, MAPP).

III. Pay attention to the appearance of the cutting torch:

1) Preheating nozzle should be made of commercial copper. Thermal stability of commercial copper is 3-4 times higher than brass and it has red colour as opposed to yellow brass.



For the acetylene cutting torch cutting nozzle should be made of copper too copper too!



2) The handle, tubes and fittings should be made of brass, copper or stainless steel.

3) Tip and injector should be removable and easily replaceable. It is important to remove it quickly in case of failure or blockage of the tip or injector. In this case you will avoid buying of new cutting torch.

4) The professional cutting torches should have a lever for cutting oxygen valve or a wing with minimum diameter - 40 mm. It's important condition of cutting oxygen valve opening and closing while continuous duty.

5) The wings of valves should spin with little effort (do not dangle but not tight turn). There is a strong probability of spontaneous misadjustment of flame during operation in case of free rotation (it is not comfortable and dangerous!). And tight turning of the valves is not convenient for adjusting or extinguish of the cutting torch. Sometimes it could be impossible.



6) Valve spindles should be made of stainless steel (its average lifetime at least 15000 operating cycles). Such spindles made of brass are prohibited because its lifetime only about 500 operating cycles, in what follows valves will leak. It may result in leakage of fuel gas and oxygen that can lead to an explosion of accumulated gas mixture.

It is acceptable to use the combined spindles – brass with stainless steel. Such is much better than the solid brass spindles.

7) Combined 6/9 nipples are not permitted to use at the cutting torches that cut metal up to 300 mm. Combined nipple 6/9 reduces the flow area by 3 times compared to the nipple Ø9 mm which is not enough to ensure the flow of gases.



8) Choose brass nipples! Aluminium nipples fail faster.





9) The spare parts should be always available at the seller! Otherwise you buy disposable product.





10) Facing of brass or copper colour hides brazing faults, metal defects or may mislead you, pretending aluminium for brass or copper.

Wish you to make correct choice!


Head of research laboratory of DONMET

Tel: +38 (0626) 44-16-01; Skype: donmetlab


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