Industrial Instrument Accessories and Other Equipment Maintenance Guide
Instrument accessories such as manifolds, impulse tubing, fittings, junction boxes, and protective housings are critical to reliable instrument operation. Proper maintenance of these components is often overlooked but essential.
I. Manifold Maintenance
- Regular Inspection: Check manifold valves for leakage through the stem packing. Tighten the packing gland if leakage is detected.
- Valve Operation: Exercise manifold valves quarterly to prevent seizing. Verify smooth operation through full range of motion.
- Leak Testing: Perform leak tests on block-and-bleed manifolds during scheduled shutdowns. Check the bleed port for proper sealing.
- Replacement: Replace manifold gaskets and packing during instrument calibration cycles.
II. Impulse Tubing and Fittings
- Inspect tubing for corrosion, mechanical damage, or vibration fatigue cracking monthly
- Check all compression fittings for tightness using the appropriate wrench size. Overtightening damages ferrules.
- Clean or replace plugged impulse lines. Consider installing rod-out fittings for applications prone to plugging.
- Verify that tubing is properly supported to prevent sagging and vibration damage
III. Junction Boxes and Wiring
- Inspect junction box seals and gaskets for integrity. Replace if degraded to maintain IP/NEMA rating.
- Check for water or moisture ingress. Install drain plugs or breather vents if condensation is observed.
- Tighten terminal connections annually. Loose connections cause signal problems and can be a fire hazard.
- Verify that unused conduit entries are properly plugged
IV. Protective Housings and Sunshields
- Clean instrument housings quarterly to prevent dirt accumulation
- Check sunshield integrity; replace if cracked or degraded by UV exposure
- Inspect mounting brackets and hardware for corrosion; replace with stainless steel in corrosive environments
- Verify that housing covers are properly tightened to maintain environmental protection
