ORIFICE PLATE IN COMPLIANCE WITH ASME B16.36
The main component of the orifice plate set complying with ASME B16.36 is made of a plate that can be supplied as a separate item, too. Its design depends on specific requirements of the customer, e.g. a centric orifice plate, segmental orifice plate, multi-bore orifice plate, restricting, eccentric etc. Its type depends on the flange face (RF, RTJ) and it is clamped between the pair of tapping flanges.
Tapping flanges use pressure tapping on the flange defined by ISO 5167-2 standard, corner tapping is possible, too. Tapping flanges are manufactured in compliance with requirements of ASME B16.36 and these are available in pressure classes ranging from 300 lb up to 2500 lb. Each set of tapping flanges is equipped with two pairs of pressure tapping, bolts, nuts, washers (gaskets) and expander bolts helping with the disc removal. Bores on tapping flanges are ended with inner NPT thread as a standard, one of which is equipped with a blind for sludge.
Flanges can be supplemented with differential pressure outlets, which are on agreement with customers always customized to various options of primary element attachment to the measuring circuit.
Orifice plate discs and sets of tapping flanges are manufactured in nominal diameters ranging from DN 25 (1“) up to DN 1,000 (40“). Upon request, set of tapping flanges with orifice plate can be supplemented with straight lengths of piping 2D “downstream” and 2D “upstream” the orifice plate.
304, 321 or 316 stainless steel grades are the most used ones for the production of plates, however, on request of the customers other materials can be used, too. On the handle of the disc there are embossed the key data – such as inside diameter of the pipes, pressure class, material, bore diameter etc. In relation to ISO/TR 15377 standard the disc can be supplemented with so-called draining holes for gases or ventilation holes for other fluids.
Centric orifice plate determined for incorporation between tapping flanges in compliance with ASME B16.36 is manufactured either as a working meter or, as a specified meter with metrological verification complying with the technical particulars and conditions of pattern approval.
Set of tapping flanges with the orifice plate provides economic and progressive method of incorporating the orifice plate metering. Since the differential pressure tapping are integrated directly in the flange body, there is no need to supply separate orifice plate flanges or, drill the pressure tapping into the pipe wall. Set of tapping flanges with the orifice plate can be incorporated both in vertical and in horizontal piping.
Set of tapping flanges can also be supplemented with rinsing rings replacing the disc during rinsing of pipe after welding or other technological interventions.
Use of flushing rings with the inner diameter equal to the diameter of piping prevents damage on the disc by carried solid particles and impurities as well as prevents its damage from aggressive temporary impact of technological fluid.