Installation conditions, advantages and disadvantages of orifice steam flowmeter

1. Installation conditions of orifice steam flowmeter
① The centerline of the standard orifice plate shall be coaxial with the centerline of the pipe.
② Orifice plate steam flowmeter shall be installed with a section of measuring pipe, which shall at least keep the first 10DN and the last 5DN straight pipe sections of equal diameter to improve measurement accuracy.
③ The inner diameter of the impulse piping is related to the length of the piping and the dirt degree of the medium. Generally, pipes with an inner diameter of 8-12mm are used within 16m.
④ The impulse piping should have a firm support. The two impulse piping should be as close to each other as possible and away from the heat source or vibration source. When measuring the steam flow, it should be wrapped with insulation materials. If necessary (such as the temperature below 0 ℃), heat tracing pipes should be added to prevent icing. Isolator or settler shall be attached when measuring the dirt flow.
⑤ Single phase fluid must always be maintained in the impulse piping. When the fluid to be measured is liquid, the pressure pipeline is full of liquid phase, and there must be no bubbles.
Therefore, the drain valve shall be installed at the lowest point of the impulse pipeline or the exhaust valve shall be installed at the highest point. Special attention shall be paid to the installation or maintenance of the differential pressure transmitter.

2. Advantages and disadvantages of orifice steam flowmeter
Advantages of orifice steam flowmeter:
① The most widely used orifice plate flowmeter has firm structure, stable and reliable performance and long service life;
② The test piece, transmitter and display instrument are produced by different manufacturers, which is convenient for economies of scale production.

3.Disadvantages of orifice steam flowmeter:
① The measurement accuracy is low;
② The range ratio is small, usually only 1:3~1:5;
③ High requirements for on-site installation;
④ Large pressure loss.
⑤ Thermal insulation treatment is required in winter, which is easy to freeze.


Post time: 01-11-22