1. ISA1932 nozzle (also known as standard nozzle): Standard nozzle is composed of two circular curved surfaces, the contraction part of the inlet and the cylindrical throat connected with it. It has simple structure and convenient installation. Throttle parts can resist erosion at high temperature and high pressure and have long service life. Suitable for measuring high-pressure steam, high-pressure water, natural gas, the highest pressure can reach 42 MPa, the highest temperature can reach 1000 C, the range ratio of nozzle is 1:3-1:5, good repeatability, no real-flow calibration, only checking the shape and geometry size, accuracy can reach (+1%); suitable for the occasion of trade settlement. The pressure of standard nozzle is taken by angular connection. According to the connection mode, it can be divided into direct welding form and flange connection form. In order to facilitate field installation and improve measurement accuracy, it can provide straight pipe section along with goods. It can also make integral connection of the pressure taking part into an integrated form.
2. Long-diameter nozzles: Long-diameter nozzles are mainly used for measuring main steam and water supply in power plants. They are used in high temperature and high pressure situations. Most of the long-diameter nozzles and process pipes are welded, which overcomes the shortcomings of poor sealing of flange connections in high temperature and high pressure measurements and improves the reliability of use. The range ratio of the long diameter nozzle is 1:3-1:5, which has good repeatability. The throttle is composed of the contraction part of the entrance made up of 1/4 elliptic arc surface and the cylindrical throat connected with it. Because the entrance of the long diameter nozzle is arc surface, it can resist erosion under high temperature and pressure and has long service life. The structure of the long-diameter nozzle is simple. The whole device consists of a section of finely machined measuring tube, nozzle and pressure-taking seat. The pressure-taking mode is diameter distance pressure-taking.