SLAM SHUT TEMPERATURE TESTS
As part of improving an already existing system, we here at Drallim are running some temperature tests on the Select a Stream Slam Shut cabinets to identify how the units function in low temperatures. In the past, previous tests on the Drallim RSV (Rotary Selector Valves) proved successful at temperatures of -40°C and have since been specified by National Grid Gas (now Cadent).in place of the previous manufacturer which failed to function and leaked prefusely at significantly warmer temperatures. The test being carried out in the picture is for the fitted pressure switch which during the test is external to the cabinet and inside the climatic oven, at this point it is as low as -7.5°C and functioning correctly. We aim to go as low as -15°C to determine how well the switch functions in much colder conditions and to see what characteristic changes become present. Thus far our tests have indicated that all continues working well and the cabinet should not experience any significant problems or intermittent faults as a consequence. Drallim have been building Slam Shut cabinets for Cadent's network regions for 9 years with a proven track record of success. We are more than happy to answer any questions in relation to the product as well as offer our services for any projects that you may need assistance with. See our website for details. www.drallim.com
Retired Gas Network Supervisor
7 年This would be a good week to field trial those cabinets
EngTechMIGEM | Project Delivery Engineer
7 年I remember installing these as part of the NG (now Cadent) projects to upgrade the pneumatic controls of all AGI slamshut devices. The issue was with temperatures at both high and low ranges, but more so the high temperatures. The steel cabinets which house the controls had significant influence on their internal parts when subjected to direct sun light. The temperatures would send the tolerance of the pressure switch, installed to ensure actuation at the necessary set point, extremely wide of the plus/minus acceptable 10% deviation of the set point. All set points would have been established under ideal conditions during the testing phase, as the cabinet doors would have been opened and normal temperatures would have been a factor on the working parts. We used to get called out to these cabinets within weeks of them being installed due to them randomly activating the slam-shut valves they controlled. Have you tested the upper temperatures to which the control switch initiates actuation? What are the now know ideal temperature ranges for these cabinets to operate in and what are the temperature profiles between the outside of the cabinet and simultaneously inside the cabinet when the door is shut for them to maintain accuracy ?