1.6.1 — Pipe Hangers, Brackets, and Fasteners
Pipe supports control vibration and stress on joints and fittings, maintain correct slope for drainage and condensate removal, and prevent excessive pipe movement during thermal expansion and contraction. Incorrectly spaced or missing supports concentrate stress at brazed or soldered joints, leading to fatigue cracking and long-term leakage.
Hanger and Support Types
Clevis Hanger
The most common adjustable pipe hanger for horizontal runs. A U-shaped yoke suspends the pipe from a threaded rod attached to the structure above. Adjustable rod length allows slope to be set precisely after installation. Used for copper, steel, and plastic pipe in HVAC/R applications. Select size to match pipe OD; a hanger too large allows the pipe to shift laterally.
Riser Clamp
Supports the weight of vertical pipe runs at floor penetrations or structural members. Two-piece band clamps tighten around the pipe and bear on a structural support. Riser clamps at each floor prevent the pipe from moving downward under its own weight and the weight of the fluid inside. Required for all vertical pipe risers above a minimum height per the applicable pipe support standard.
Pipe Clamps and Straps
Simple band clamps, snap-in clips, or formed straps that fasten pipe directly to framing, walls, or structural members. Used for short horizontal or vertical runs where overhead suspension is not practical. For below-ambient (refrigerant and chilled water) piping, insulated pipe clamps with a closed-cell insert prevent the bare metal clamp from creating a thermal bridge and a condensation point at each support location.
Spring Isolation Hangers
Hangers fitted with a coil spring or rubber-in-shear isolator between the pipe and the support structure. Used to isolate vibration from compressors, pumps, and fans and to prevent transmission of mechanical noise into the building structure. Required near vibration-generating equipment where rigid supports would transmit noise and stress into the piping system.
Hanger Spacing Requirements
Maximum Spacing for Copper Tube (Typical)
Hanger spacing for copper tube is governed by the pipe size, wall thickness (Type K, L, or M), fluid temperature, and the applicable mechanical code. The following are common maximum spacings for horizontal copper tube runs as a general reference — always verify against the project specification and the authority having jurisdiction:
- 12 mm (1/2 in) copper: maximum 1.5 m (5 ft) horizontal spacing
- 19 mm (3/4 in) copper: maximum 1.8 m (6 ft) horizontal spacing
- 25 mm (1 in) copper: maximum 2.4 m (8 ft) horizontal spacing
- 35 mm (1-3/8 in) copper: maximum 3.0 m (10 ft) horizontal spacing
- Vertical copper runs require a riser clamp or support at every floor and at intervals not exceeding 3.0 m (10 ft)
- Supports must be located within 300 mm (12 in) of each fitting, valve, or change of direction regardless of the general spacing rule
Fasteners and Anchoring
- Concrete anchors: wedge anchors or drop-in anchors for attaching threaded rod to concrete slabs and walls; select the correct anchor for the base material and load; verify embedment depth and edge distance per manufacturer’s specifications
- Wood framing: lag screws or structural screws through the hanger plate into wood joists or studs; minimum two screws per hanger plate to prevent rotation
- Steel framing: beam clamps or unistrut channel clips for attaching threaded rod to structural steel; confirm load rating for the pipe size and span
- Dissimilar metals: direct contact between copper pipe and steel hangers in wet or humid environments can cause galvanic corrosion of the steel; use plastic-coated or copper-plated hangers, or insert a dielectric insert between the pipe and the hanger
- Never hang refrigerant or plumbing pipe from other pipe, conduit, or ductwork — each system must be independently supported
Install all hangers and verify pipe alignment before making brazed joints. A pipe run pulled into position by drawing up a hanger after brazing puts mechanical stress on the brazed joint while it may still be at elevated temperature — this can crack the joint. Plan the support layout so the pipe sits naturally in the hangers with no stress before any heat is applied.