Dresser Style 40 Long Body Coupling

For Widely Separated Pipe Ends — Cast Iron & Steel Pipe

Overview

The Dresser Style 40 Long Body Coupling is an engineered mechanical pipe coupling designed for applications where pipe ends are widely separated — a common field condition during repairs, replacements, or installations where a standard-body coupling cannot span the gap. Structurally similar to the Style 38, the Style 40 features a longer middle ring with a larger belly diameter, enabling it to bridge gaps that would otherwise require a spool piece or additional fittings. Despite its added length, it delivers identical expansion and contraction performance to the Style 38 — absorbing up to 3/8 in of joint movement — making it suitable for environments subject to thermal cycling, ground settlement, or vibration.

The coupling operates on a three-part assembly: two steel followers compress Grade 27 Buna-S rubber gaskets against the pipe OD via AWWA-compliant bolts and nuts, while the elongated middle ring bridges the gap and contains the fluid pressure. No threading, beveling, or precise pipe alignment is required — installation is accomplished with standard hand tools in the field or ditch.

Key Features

• Extended Middle Ring: Longer body with increased belly diameter bridges wider-than-normal pipe gaps without spool pieces or additional fittings.
• 3/8 in Expansion & Contraction Absorption: Handles thermal movement, settlement, and vibration — identical performance to Style 38 despite the longer body.
• No Pipe Preparation Required: No threading, beveling, or precise alignment. Installs with standard wrenches directly in the field.
• Fusion-Bonded Epoxy Coating: Interior and exterior corrosion protection for buried or exposed service in water and wastewater systems.
• AWWA C 111 / ANSI A21.11 Bolts: Industry-standard T-head bolts and hex nuts ensure consistent, predictable joint assembly and torque.
• Grade 27 Buna-S Gaskets: Proven synthetic rubber compound compatible with potable water, wastewater, and most industrial fluids.
• Angular Deflection Capability: Allows pipe curves to be laid using straight pipe segments without bends or elbows (see deflection table).
• Wide Size Range: Available from ½ in through 24 in for both steel and cast iron pipe. Special and larger sizes available upon request.

Materials of Construction

Specifications — Cast Iron Pipe (2 in – 24 in)

Middle ring thickness (A&B) × length. Bolt diameter × length. Overall dimensions taken with fasteners drawn up finger tight.

Pressure ratings based on Barlow's formula using working stress = ½ minimum yield of middle ring. Consult factory for ratings specific to your application. Special and larger sizes available upon request.

Specifications — Steel Pipe (½ in – 24 in)

Installation Instructions

? SEAL ONLY — This product provides a pressure seal only. When pipe pullout could occur, the pipe joint MUST be anchored. Failure to anchor the pipe joint could result in escaping line content and cause property damage, serious injury, or death.

1. Surface Preparation: Clean all dirt, rust, oil, and loose scale from the pipe end. Inspect the gasket contact area for gouges or grooves that could impair the seal. The pipe OD must fall within the specified range of fit for the selected coupling size.
2. Mark Centering Reference: Measure back on each pipe end one-half the middle ring length plus two inches and place a chalk mark. These marks are used to center the coupling over the joint.
3. Install Followers: Slide followers over each pipe end, beveled face toward the pipe end.
4. Lubricate Gaskets: Wipe gaskets clean. Lubricate each gasket, the pipe OD, and the middle ring flares with soapy water or a non-petroleum base lubricant. Add antifreeze in freezing weather. Do not use petroleum-based lubricants — these degrade Buna-S gaskets.
5. Position Gaskets & Middle Ring: Slide gaskets over each pipe end. Assemble the middle ring on one pipe end, seating the gasket against the ring flare.
6. Stab Joint: Insert the other pipe end into the middle ring. Center the coupling between the chalk marks. The pipe end must extend past the end of the gasket by a minimum of one inch after deflection has occurred.
7. Install Hardware: Install AWWA T-head bolts and hex nuts. Draw up finger tight, ensuring all hardware is properly seated.
8. Final Torque — Cross Pattern: Tighten nuts on opposite sides alternately, drawing up followers evenly. Tighten to the torque values below. Verify torque on all nuts prior to backfilling.
   • 3/8 in & ½ in Bolts — 35 Ft. Lbs.
   • 5/8 in Bolts — 75 Ft. Lbs.
   • ¾ in Bolts — 90 Ft. Lbs.

Note: For products using one gasket only, reduce torque values by half.

Recommended Laying Deflection Per Coupling

Questions? Contact us at sales@watermainsupply.com or call 281.664.8000.