Crystal APM Advanced Pressure Module - Manual (Page 4)

Operation  2
APM CPF Series Operation Manual
Operation
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ADVANCED PRESSURE MODULE (APM) INSTRUCTIONS
Pressure Connection
Crystal CPF System: Medium Pressure Female (MPF) (1/4” medium pressure tube system with 7/16-20 threads). See our CPF Brochure for further information.
CPF o-ring size and material: AS568A-012, Viton 80 durometer (P/N 3981).
For most applications CPF Fittings can be hand tightened for use up to 10 000 psi / 700 bar / 70 MPa (no tools required). Wrench tightening is recommended
(to achieve a metal to metal cone seal) for applications where chemical compatibility of the process fluid and the o-ring are a concern, or for pressures above
10 000 psi / 700 bar / 70 MPa. We recommend a tightening torque of 120 in-lbs ±20 in-lbs. Please note this is only a fraction of the typical torque required to
seal a 1/4” NPT fitting. If a torque wrench isn’t practical to use, the fittings can be assembled as follows: Hand tighten fitting fully until the cone has bottomed
out. Tighten an additional 20º using a wrench. Apply a small amount of media-compatible lubricant to the gland threads and male cone to increase fitting life,
reduce the likelihood of galling, and promote sealing.
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CAUTION: To achieve CPF maximum allowable working pressures no o-ring substitutions are allowed. See our CPF brochure and CES-003 CPF Safety
Guide available from the website at crystalengineering.net for further detail.
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WARNING: Pressurized hoses and associated equipment are potentially dangerous. Slowly bleed off pressure from the system being pressurized prior
to connecting or disconnecting the Crystal APM.
Measuring Vacuum
All ranges of the APM can be used to measure moderate vacuum. Ranges 300 psi / 30 bar / 3 MPa and below are calibrated for vacuum use.
When measuring pressure less than ambient barometric conditions, a minus sign (-) will appear.
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CAUTION: The APM is not recommended for continuous use at high vacuum.
Overpressure Conditions
The APM will read pressure up to approximately 110% of the rated pressure range. All JOFRA indicators will display overpressure warnings. For example,
above 110% of the range, “OL” will display in red on an ASC-400, indicating an Overload Alarm. The zero function does not affect when the “OL” is displayed to
indicate overpressure. So depending on the zero value, it is possible that the display will indicate “OL” without the maximum pressure being displayed.
For instance, if a 100 psi APM is zeroed when 30 psi is being applied, it will indicate that the overpressure condition has been reached at 80 psi.
(i.e., 110% x 100 psi – 30 psi = 80 psi).
Overpressure can affect accuracy, but the effect is only temporary unless the sensor has been damaged. See Specifications for maximum allowable overpres-
sure ratings.