Blister on a 20K Hose
During pre-job inspection, a crew lays out six 20,000 psi hoses. Hose A has a 1/8-in. cover abrasion with one wire visible 6 in. from the coupling. Hose B has a soft blister 2 in. from the crimp with the cover intact. Hose C has no date tag but 'looks new.' Hose D has a pinhole leak at the ferrule that stops when the hose is bent. The supervisor wants to cut the damaged ends off A and D and re-crimp them in the field with a portable crimper, then put all six back in service because the turnaround window is 4 hours. The pump relief valve is set at 22,000 psi, and the lance gauge reads zero even though the pump is running. No hose test records are on site, and the crew has no spare high-pressure hose.
1. Give the disposition for each hose and explain the reasoning.
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- Hose A: Remove from service. A visible wire means the reinforcement barrier is breached, and the abrasion is close to the coupling where flexing concentrates stress. Taping or cutting back does not restore the original crimp or proof rating.
- Hose B: Remove from service. A soft blister with an intact cover can indicate fluid intrusion, trapped gas, or internal damage. The cover being intact is not evidence of integrity; the blister is a deformation that can burst under pressure.
- Hose C: Do not use until records or a date code are verified. 'Looks new' is not a traceable inspection. Without a date tag or test record, the hose cannot be confirmed to be within its service life or to have been proof-tested.
- Hose D: Remove from service. A pinhole leak at the ferrule that stops when the hose is bent is a classic sign of a damaged crimp or fitting. Bending may temporarily seal it, but pressure will reopen it, possibly as a violent failure.
None of these hoses should be returned to 20,000 psi service based on a visual 'looks okay' judgment.
2. Evaluate the supervisor's plan to field re-crimp hoses A and D with a portable crimper.
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Field re-crimping of 20,000 psi hose is not an acceptable repair. The crimp must match the hose and fitting manufacturer's specification, including the correct die, crimp diameter, and push-on length. A portable crimper used without the manufacturer's calibration and procedure can produce a fitting that passes a static look but fails under pressure or cyclic loading.
Cutting off the damaged end also changes hose length and may leave damaged reinforcement near the new fitting. Even a correctly made field repair would need the appropriate proof test and documentation before being placed in 20,000 psi service. The supervisor's plan trades a 4-hour schedule problem for an uncontrolled pressure-release hazard. The correct decision is to remove A and D from service and obtain tested replacement hoses or a qualified repair.
3. What should be done about the relief valve setting, the zero-reading lance gauge, and the missing test records?
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The relief valve at 22,000 psi is set above the 20,000 psi hose rating, so the hose can see pressure above its rating before the relief lifts. The relief should be set to protect the lowest-rated component in the system and verified with a calibrated gauge; it should not be used as an operating pressure control.
A lance gauge reading zero while the pump is running means the gauge is isolated, broken, or connected incorrectly. Do not pressurize until a calibrated gauge is installed and the reading is verified at low pressure. Missing test records mean the hoses cannot be confirmed as current. The crew should treat the records as part of the inspection: no traceable test, no service. The schedule pressure is not a reason to skip relief verification, gauge checks, or hose documentation.