Most of the pressure incidents I've seen in 20 years didn't come from bad parts. They came from good techs in a hurry, skipping a step they knew they shouldn't skip. If you're new to instrument and process work, or you're training someone who is, these are the habits worth building on day one.
1. Treat Every Line as Live Until You Prove It Isn't
A line that "should be" dead is not the same as a line that is dead. Follow your site's lockout/tagout procedure every time, even for a five-minute job. Close and lock the isolation valves, then bleed the section you're working on through a vent or bleed valve, not by cracking a fitting.
Then verify zero. Read a gauge on the isolated section, and remember that a gauge can stick or fail. If you have a second way to confirm, such as a bleed valve that stays quiet when opened, use it. Watch for trapped pressure between two closed valves and in valve body cavities.
2. Never Tighten a Fitting Under Pressure
This is the one I'd tattoo on every new tech if I could. Putting a wrench on a pressurized fitting can strip threads, crack a ferrule loose, or blow a component apart in your face. If something leaks, isolate and depressurize first. Then fix it.
3. Find Leaks With Leak Detector, Not Your Hand
A pinhole leak in a high-pressure gas or hydraulic line can cut skin or inject fluid under it. Never run your hand along a line to feel for a leak.
Once the line is pressurized per your site procedure, apply Gator Leak Detector all the way around each joint you touched and watch for bubbles or foam. On male connectors and other NPT-to-tube fittings, check the pipe-thread joint as well as the tube nut, since the NPT side often gets skipped. If something leaks, go back to habit #2: isolate and depressurize before putting a wrench on it.
4. Know the Rating of Everything in the Line
A system is only as strong as its weakest part. Before you add a valve, hose or fitting, check that its pressure and temperature rating fit the service, and that the tubing size, wall thickness and material match what the fittings are made for. Don't "make it work" with whatever is in the truck.
Brand mixing is one place you have solid backing. DK-Lok tube fittings are 100% interchangeable and intermixable with Swagelok and Parker A-Lok, for like size and material, properly assembled per the DK-Lok catalog. In ASTM F1387 testing witnessed by TÜV Rheinland, 14 combinations of intermixed DK-Lok and Swagelok nuts, ferrules and bodies passed every test, with "No failure observed." See also the Parker A-Lok interchangeability letter.
5. Respect Hoses and Stored Energy
A hose that lets go under pressure can whip hard enough to break bones. Inspect hose assemblies before use, route them away from walkways and sharp edges, and use whip restraints where your site requires them. Don't stand in line with an end connection while a system is coming up to pressure.
6. Wear the Gear and Stop When It Feels Wrong
Safety glasses at minimum, plus the gloves and face protection your job calls for. And if something doesn't look or sound right, stop and ask. Nobody who's been doing this a long time will think less of you for it.
Free Safety Training for Your Crew
A-Best Industrial Inc. Fittings, Valves, and Tubing offers a free safety training course for new and existing customers. It's a good fit for new hires and a good refresher for experienced crews. Learn more on our training page.
We're Here to Help
To book a class or get help with a job, call A-Best Industrial Inc. Fittings, Valves, and Tubing at 310-833-3353 or email sales@abesttube.com. We're open Monday–Friday, 8:00 AM–5:00 PM Pacific, with after-hours emergency service.