Instruction Leaflet for Pressure Gauges
WARNING:
Incorrect use of pressure gauges can cause damage end injures. Under this Directive, the user must ensure that pressure gauges are installed and used in such a way that pressure-related hazards are eliminated to a maximum extent.
Before starting installation, follow the recommendations of standard AS-1349.
Check that the pressure gauge is suitable for the planned use in terms of:
• Operating pressure (OP)
• Operating temperature (OT)
• Safety level of the pressure gauge
• Connection interface
• Type of mounting
• Compatibility of materials in contact with the fluid to be measured
• Environmental conditions, vibrations, shocks, pulses, ambient atmosphere
• Check that the pressure gauge is compatible with the surrounding atmosphere
USE IN AN OXYGEN CIRCUIT
Check that the pressure gauge is designed for such an application. The dial must have the word “OXYGEN” printed in black letters and “USE NO OIL” in red letters. The pressure gauge must not have been in contact with oil or grease that is incompatible with oxygen: RISK OF EXPLOSION!
Mounting
A pressure gauge must be mounted in compliance with standard practice
• We advise to mount with an isolation valve.
• The user must check that the connections are perfectly seated by using suitable seals that are compatible with the fluid to be measured.
• Use a correctly sized spanner to tighten connections NEVER TWIST THE CASE IN ORDER TO TIGHTEN CONNECTIONS
• Comply with the instructions given on the device when putting it into service.
• For pressure gauges fitted with a rear blow-out disc for protection against overpressure, ensure that there is a gap of at least 10 mm between the rear panel of the casing and the panel immediately next to it.
• Likewise, for this type of rear blow-out disc and a casing filled with damping fluid, do not remove the disc from its location
• Only re-use a pressure gauge if the medium is the same as for its first use.
USE
Warning: The operating conditions must be such that the device can be used safely
THE PRESSURE GAUGE MUST NOT BE SUBJECTED TO:
• Mechanical shocks: if there is a risk, install it at a distance with a hose connection
• Vibrations: if there is a risk, install it at a distance with a hose connection or use a liquid fitted pressure gauge.
• Pressure pulses: if there is a risk mount a pulsation damper
Warning: pressure pulses cause a considerable shortening of the operating life of pressure gauges.
• Pressures greater than operating pressures (OP) Otherwise use a pressure relief valve
• Temperatures greater or less than operating temperatures (OT). If there is a risk use a siphon mount or mount with hose connection to respect the temperature at the pressure gauge.
NOTE: Failure to observe the conditions above may reduce pressure gauge safety.
DISASSEMBLY
• During disassembly, check that the pressure gauge is no longer under pressure. As a precaution, disassemble it slowly
• Check that the temperature of the pressure gauge body is not sufficient to cause burning.
• Check that residues of the product present in the tube and block of the pressure gauge are not dangerous for the operator and the environment.
MAINTENANCE
• The general safety of a facility often depends on the reliability of indications on the pressure gauges installed in the facility
• Any pressure gauge that seems to be giving false readings must be removed immediately, then tested. If the tests prove it is unreliable, it must be replaced with a new device.
• Periodic verifications should be carried out to check the accuracy of pressure gauges
• Any pressure gauge considered to have been subjected to abnormal conditions of use (e.g. fire, wrong fluid, etc.) must not be used
MAINTENANCE, VERIFICATION OR RECALIBRATION MUST BE CARRIED OUT BY PERSONNEL APPROVED BY THE CONSTRUCTOR AND USING SUITABLE EQUIPMENT.
Mounting
Pressure gauges are mounted in the following ways:- Direct mount, bottom entry (most common, mounted by process connection at the 6 o’clock position Direct mount, rear entry (process connection at the rear of gauge, either centre rear or bottom rear. Surface mount, bottom entry (rear three hole mounting flange for wall mounting, process connection at the 6 o’clock position Flush mount, rear connection (front three hole mounting flange for hole mounting, process connection at the rear of gauge, either centre rear or bottom rear. Panel Mount, rear connection, (“U” clamp hole mounting, process connection at the rear of gauge, either centre rear or bottom rear.