HOW TO SELECT A PRESSURE GAUGE 

Selecting a pressure gauge: the subjects listed below can be used as a guide to ensure to ensure that proper
consideration is given to all factors affecting the choice of a pressure gauge.

(caution: operating conditions including, but not limited to, system pressure,media compatibility and ambient 
conditions must be considered when selecting gauges could cause gauge failure and lead to possible property 
damage and personal injury.)

1) PRESSURE RANGE: Select a range so that the expected operating pressure falls in the middle half of the

gauge (25% to 70% of full scale), if short duration pressure pulses are expected , the range may need to be 

increased to avoid damae to some types of guage . normally range from 0 psi to 10000psi and vacuum can be

tested with bourdon tube .so can select bourdon tube gauge , but micro pressure, (for example 160mbar) should 

be tested with capsule . so have to select Capsule gauge. 

2) Operate Condition: Normal condition in house, and no vibration and pulsation, we can select dry gauge, but

if there are vibration and pulsation in the system, we should choose liquid filled gauge protect the normal indic-

-ating pressure in the gauge. And if the system need to control with the pressure. We can choose electrical contact

gauge or pressure switch or pressure transmite to replace the normal gauge. If you are considering a gauge which

will be an operator, a process gauge with a soild front construction will provide an extra measure of safety, if you

require in -house calibration, specify a micrometer adjustable pointer and bayonet ring case, while a large case

will be easier to read, case size consideration are generally driven by available space, connecting considerations

and accuracy requirement.

3) Environmental consideration: if  the gauge will be used in normal condition, such as normal air, the case can

be made of steel powder coated black or chrome plated, or plastic, but if the environment is severe or corrseive, a

stainless steel case may be indicated.

Ambient temperature, humidity, vibration, corrosive gasses, and weather must all be considered when selecting a

pressure gauge, the environmental temperature limits for most shunjay pressure gauges are shown in the table

beloe. Generally all shunjay pressure gauge are dust proof, and filled gauge or fillable gauge are water proof.

ENVIRONMENTAL LIMITES
DAMPING FLUID	RECOMMENDED TEMPERATURE RANGE
Dry	-13 to 150° F	-25 to 65°C
Glycerine	60 to 150° F	-15 to 65°C
Silicon	-50 to 150° F	-45 to 65°C

Working Fliud: normal fluid such as air , water ,and inert gas can use copper alloy as the wetted parts , but If 
the working fluid is corrosive , stainless steel wetted parts should be considered ,and acytelen need to use brass
wetted parts. And oxygen need wetted part oil prohibiting . we can use diaphragm sealed pressure gauge to
measure the corrosive fluids pressure , where suitable material for bouden tube is not avalible . also diaphragm
sealed gauges can be used for systems needing contact surface that ar, e&nbs, p, ;rigorously cleaned and totally safe, the
function of the diaphragm is to isolate the pressure gauge from the process fluid , preventing bacteria developing
inside pressure gauges sensing element.and easy to clean and quick release coupling.

Mounting: as a rule , all gauges are available in stem mount, lower connected and stem mount , back connected,
not all gauges re available in all mouting configuration for a sketch of mouting types see the mounting codes
examplesillustration as below table, if your application involves excessive vibration or requires a large gauge,
consider specifying a gauges which is mounted buy some method other than the stem , for  example , U-clamp or
surface mount gauge , this will reduce the stress on the stem and promote more reliable operation.

Connection : Shunjay pressure gauges are availbe in a wide variety of connection , BSP threads are the standard
configurtion, if you have a requirement for a connection not listed , contact with Shunjay.

options: BSP, BSPT, NPT, Metric thread, hose connection