Dresser Style 38 Bolted Coupling - Cast & Ductile Iron Pipe

Dresser Style 38 couplings have long been used to join plain-end cast iron and ductile iron pipe, giving a tight joint and faster pipe joining. They also let you salvage random lengths of cast or ductile pipe from which bell ends or cracked sections have been cut.

Application: Joining and repairing plain-end cast iron and ductile iron water and wastewater mains.

• Sized to cast and ductile iron ODs, not steel
• Salvages cut lengths with bells or cracks removed
• Absorbs vibration, expansion and deflection at the joint
• Fusion-bonded epoxy inside and out

NSF/ANSI 61 and 372 certified per Dresser’s 2024 Water Pipe Joining catalog. Only products bearing the NSF mark are certified.

Up to 1,500 PSI on the smallest size, falling as diameter rises (218 PSI at 48 in). The allowable pressure on a job also depends on the pipe, its condition and the workmanship. For 3 through 12 in with one coupling that fits several pipe classes, see the Style 138 (250 PSI).

Source: Dresser Style 138/38 cast and ductile iron data sheet and 2021 submittal.

Plain-end cast iron and ductile iron pipe, matched by OD. Cast iron made over the last century varies by class and maker: measure the OD before ordering.

Laying deflection per coupling (Dresser guide): 6° for 1/2 to 2 in OD and 4° above 2 through 14 in OD on 5 and 7 in middle rings; 2° (5 in ring) or 4° (7 and 10 in rings) above 14 through 30 in OD; less on larger sizes.

Sizes as listed in Dresser’s 2026 price lists; the picker shows the part number for each build.

• Clean dirt, rust, oil and loose scale from each pipe end, and check the gasket seats for gouges or grooves (Dresser installation guide, tag 0001-0737-999).
• Mark each pipe end at half the middle ring length plus 2 in, and center the coupling between the marks.
• Lubricate gaskets, pipe OD and middle ring flares with soapy water or a non-petroleum lubricant.
• Each pipe end must sit at least 1 in past the end of its gasket after deflection.
• Tighten nuts on opposite sides to draw the followers up evenly to the torque in the guide, and check every nut before backfilling.
• Anchor the pipe: the coupling provides a pressure seal only, and Dresser requires the joint to be anchored wherever pipe pullout could occur.

From the Dresser installation and torque guide for Styles 38, 40, 56, 62, 69, 71, 72, 76, 89, 128 and 168 (in the Data Sheet tab). Torque values stay in the guide.