A Cure for Valve Disease
Page 32
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I N view ot the fact that, operators cannot look to a cure for. their, present-day valve troubles in a change of. fuel, it is felt that they will be interested in a process of valve treatment or reclamation that, it is claiMed, will put an end to the malady.
The Depochrome process, as it is called, is not entirely new, as, for many years past, the company responsible has been treating the exhaust valves of oil engines, such as are used in generating• and pumping stations, with marked success. Hitherto the concern has had little occasion to interest itself in commercial 'vehicle engine valves, as operators have found it convenient to use standard replacement valves when
the need has arisen.
Valves being in short suriply, and
this at a time when valve trouble is particularly prevalent, has induced the company to interest itself, to a greater degree, in ,the small engine field. The process consists in building up the burnt valve, by high-temperature fusion, with a layer of metal 'containing an unusually high percentage of chromium. The refacing of the valve is carried out, either by wet or dry grinding, any normal type of garage valve-facing machine being suitable.
If desired, valves so treated can be returned to the operator ready for fitting, but, naturally, an extra charge is made for the refacing. The metal, as deposited, has a Brinell reading of over 700, and it is claimed that it is not adversely affected by the exhaust gases or heat. We 'have, examined several valves which have been reconditioned in this way and, basing our remarks on the success which has already been achieved, we are of the opinion that it is a practical means for combating a most disturbing factor in commercialvehicle operation.
• It may be pointed out that there is some considerable advantage attached to. the building up of new valves by the Depochrome process before they are put into service. By adopting this procedure is to practise protection, as against the more expensive method of applying a cure.
We understand that the charges are moderate, being from 2s. Per valve upwards, according to the diameter of the valve. All inquiries shouldsbe made direct to the Nichoff Welding and Engineering Co., Ltd., 12, Warner Street, Mount Pleasant, London, E.C.1.