NCCER Pipelayer cheat sheet

Trench spoil and materials are kept at least 2 ft (0.6 m) back from the trench edge to reduce edge loading and keep the excavation access clear.

A ladder or ramp is required in any trench 4 ft (1.2 m) or deeper, placed so a worker travels no more than 25 ft (7.6 m) to the nearest exit.

Competent person: a person capable of identifying existing and predictable hazards and authorized to take prompt corrective action; trench inspections occur before entry, after rain, and after any hazard change.

Spoil piles, equipment, and materials must never be stacked so they block the trench exit path or surcharge the trench wall.

Pipe in storage is blocked or chocked; round pipe is never stacked in a pyramid beyond the manufacturer's recommended height, and workers never stand in the roll path of pipe on a slope.

Confined-space entry into a manhole or vault follows the site permit: atmospheric testing, ventilation, attendant, and retrieval system before entry.

Utility locate call (such as 811 in the US) precedes excavation; the tolerance zone around marked utilities is hand-dug, not machine-dug.

Daily pre-shift inspection includes trench walls, shoring, ladders, water accumulation, and the location of underground utilities.

PVC sewer pipe is joined with a gasketed bell-and-spigot push joint; the spigot end and gasket are lubricated with manufacturer-approved lubricant, and a witness mark shows full insertion.

Ductile iron push-on joints use a rubber gasket seated in the bell groove; the pipe is pushed home to the witness mark with a bar or jack, never by striking the pipe.

Concrete pipe joints: bell-and-spigot with rubber gasket, tongue-and-groove, or butt joint; mortar is used only where the specification permits and never substitutes for the gasket.

HDPE is commonly joined by butt fusion, electrofusion, or mechanical fittings; the fusion bead is inspected and the joint is allowed to cool before handling.

Corrugated metal pipe (CMP) uses couplers or band joints; the band is centered on the joint and the bolts are torqued to the specified value.

Clay (vitrified clay) pipe is joined with flexible compression couplings or gaskets; it is brittle and is handled with slings, not chains or hooks.

Fittings include bends, tees, wyes, reducers, and adapters; a transition between dissimilar materials uses a manufactured adapter or coupling, not mortar or tape.

Pipe marking identifies material, size class, and standard: PVC sewer pipe follows ASTM D3034 (SDR) or F679, ductile iron follows AWWA C151, and concrete follows ASTM C76.

A trench is an excavation deeper than it is wide, with a maximum width of 15 ft (4.6 m) at the bottom; wider excavations are governed by excavation, not trench, rules.

Spacing of shoring members and the soil classification (Type A, B, or C) come from the tabulated data supplied with the protective system; the tabulated data is kept on site.

Sloping and benching: Type A soil may be sloped 3/4:1 (H:V), Type B 1:1, and Type C 1-1/2:1; the classification is made by a competent person.

Type C soil cannot be benched; it is sloped at 1-1/2:1 or supported with a protective system.

Trench shield (trench box): workers stay inside the shield, the shield is not dragged with workers inside, and the bottom of the shield is not more than 2 ft above the trench bottom unless the tabulated data allows it.

Water accumulation is controlled with pumps and ditching; an employee does not work in water that is above the bottom of the protective system's lower member.

Spoil, equipment, and materials are kept at least 2 ft from the edge of the excavation; the distance is increased when the soil is unstable.

Air monitoring is required before entry where a hazardous atmosphere may exist, and testing is repeated as conditions change.

Grade (slope) is the vertical drop per unit of horizontal run and is set with a laser or optical level; the pipe invert elevation, not the pipe crown, controls the grade.

Laser setup: the laser is set on the pipe grade line, and the target or detector reading is checked against a known benchmark before laying begins.

Pipe bedding: the bedding is shaped to support the pipe barrel, and the bell hole is dug so the bell does not carry the pipe's weight.

Laying proceeds upgrade (uphill) with the bell facing upgrade, so the spigot enters the bell on the push; the joint is checked for full insertion.

Alignment is checked with a laser, stringline, or offset line; the pipe is brought to line before the joint is fully seated and backfill begins.

Backfill is placed in lifts and compacted per the specification; the initial backfill around the haunch (lower quarter of the pipe) is the most critical for support.

Deflection testing of flexible pipe uses a mandrel or go/no-go gauge; deflection is checked after backfill and before acceptance.

Infiltration/exfiltration or low-pressure air testing verifies joint tightness; the test method and allowable rate are specified before the line is accepted.