Dresser Style 40 Long Coupling - Steel Pipe, 1/2 in to 24 in

Dresser Style 40 long body couplings join pipe when the gap between the ends is wider than ordinary. They are built like the Style 38, with a longer middle ring and a larger belly diameter, and absorb the same expansion and contraction: up to 3/8 in per joint.

Application: Closing wide gaps between plain-end steel pipe ends without a spool piece.

• 12, 16 and 24 in middle rings
• Absorbs up to 3/8 in expansion and contraction per joint
• Same followers, gaskets and bolting as the Style 38
• Gasket grades for water, oil and high-temperature service

NSF/ANSI 61 and 372 certified in Grade 27 and EPDM per Dresser’s 2024 Water Pipe Joining catalog. Only products bearing the NSF mark are certified.

Up to 1,500 PSI on small sizes, falling as diameter rises. The allowable pressure on a job also depends on the pipe, its condition, the service and the workmanship.

Source: Dresser Style 40 submittal and 2024 Water Pipe Joining catalog.

Plain-end steel pipe, standard and odd ODs, where the pipe ends sit too far apart for a Style 38.

Gasket grades on this listing: Grade 27 Buna-S is the standard for fresh and salt water, natural gas, air, most acids and alkalis; Grade 42 Buna-N (Nitrile) resists oil, hydrocarbons and gasoline; both are rated to 212°F. Armored gaskets carry a brass coil molded into the tip for metal-to-metal contact where cathodic protection current must pass. Grade 365 graphite fiber is for high-temperature, abrasive service to 1,200°F, carries no pressure rating, and may not give a leak-proof seal (Dresser gasket overview).

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.

• 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.