Selection of pressure gauge for measuring ammonia solution as the medium
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I’m a complete novice. I would like to ask the experts: when measuring corrosive liquids such as ammonia, is it necessary to use a diaphragm pressure gauge with a bend? If it’s not necessary, can the header be directly screwed onto the switch ball valve of the pressure gauge? If measuring air, can a regular pressure gauge be used?
There are special pressure gauges for ammonia; diaphragm pressure gauges usually come with flanges, and no elbow fittings are required in this case. Air can be measured with a regular pressure gauge without any problem.
For the installation of pressure gauges, specifications require the use of a condensation elbow when the medium temperature is above 60°C. Diaphragm pressure gauges do not require a condensation elbow, as the diaphragm acts as a barrier preventing the medium from coming into contact with the Bourdon tube, thus preventing temperature from affecting it. However, the diaphragm and sealant must be able to withstand the temperature of the medium.
I am from a instrumentation manufacturer; you can consult me regarding the selection of pressure instruments. 2881036796
I am from a instrumentation manufacturer; you can consult me regarding the selection of pressure instruments. 2881036796
Ammonia has special pressure gauges; in other words, the material of the liquid-contacting components is special.
For measuring ammonia, a diaphragm pressure gauge should be used; it is necessary to inform the manufacturer that it is for measuring ammonia, and the diaphragm material must be resistant to ammonia corrosion. For measuring air, a regular pressure gauge will suffice~~
To measure ammonia, a stainless steel pressure gauge can be used; with a diaphragm pressure gauge, there is no need for elbows – it can be screwed on directly. If measuring air, can a regular pressure gauge be used? Yes
When using ammonia, copper prohibition is a key consideration.
When considering the material selection for instruments, pure liquid ammonia (anhydrous ammonia) requires specialized materials; the use of copper-containing materials is strictly prohibited. In the case of ammonia solution, the choice of material depends on the concentration and temperature – for low temperatures and low concentrations, stainless steel can be used (20# steel is used for process pipelines, while instrument materials are generally of a higher quality than those used in processes)