Replacing an RV holding-tank drain valve starts with more than the pipe diameter. The inlet and outlet connections, valve body, and way the handle operates all need to match the existing waste system. Valterra makes manual pull-handle valves and cable-operated versions for locations where reaching the valve directly is difficult. This guide compares five individual Valterra part numbers and the connections that distinguish them.

Compare Valterra waste-valve connections

Part number Valve and pipe connection How it operates
T1001 1½-inch spigot × 1½-inch hub Direct pull handle
T1002B 2-inch hub × 2-inch hub Direct pull handle
T40B 3-inch hub × 3-inch hub Direct pull handle
TC172 1½-inch valve body with 72-inch cable Remote cable handle
H40H72 3-inch hub × 3-inch spigot 72-inch remote cable

What hub and spigot mean

A hub is a socket-shaped fitting that receives a compatible pipe or spigot. A spigot is a smooth fitting end that goes into a matching hub. The sizes describe nominal plumbing connections; a valve marked 1½ inches is not interchangeable with a 2-inch or 3-inch assembly just because it looks similar in a photo. For example, the Valterra T1001 has different ends, whereas T1002B and T40B use hubs on both sides.

Before ordering, examine where the original valve joins the plumbing. Check pipe diameter, solvent-weld connections, mating flanges, handle reach and clearance from adjacent pipes. If the original assembly has bonded fittings, plan for the replacement work rather than assuming the valve will simply unbolt from the pipe.

Matching waste valves and product photos

T1001 — 1½-inch manual waste valve

Valterra T1001 1-1/2-inch manual RV waste valve, spigot-to-hub configuration

A fixed-connection manual valve; match both pipe ends before choosing it.

View Valterra T1001

T1002B — 2-inch manual waste valve

Valterra T1002B 2-inch hub-to-hub RV waste valve with manual pull handle

Two fixed hub ends. Do not substitute it for a 1½-inch or 3-inch pipe arrangement.

View Valterra T1002B

T40B — 3-inch manual waste valve

Valterra T40B three-inch hub-to-hub manual RV holding-tank waste valve

For matching 3-inch pipe runs where both sides require a hub connection.

View Valterra T40B

TC172 — 1½-inch flexible cable valve kit

Valterra TC172 1-1/2-inch waste valve kit with 72-inch remote-control cable

Valterra's 72-inch flexible cable kit uses a stainless-steel inner wire and folding handle. Confirm the valve body matches your flange assembly.

View Valterra TC172

H40H72 — 3-inch pre-attached cable valve

Valterra H40H72 3-inch hub-to-spigot RV waste valve with remote cable handle

A pre-attached cable valve with unequal pipe-end styles. Identify which side of the installation requires the hub and which requires the spigot.

View Valterra H40H72

When a cable-operated waste valve is useful

On some RVs, the valve is concealed behind a compartment or positioned where its handle is difficult to reach. A cable-operated valve lets the control handle sit in a more accessible location while the valve remains at the holding tank. Valterra TC172 is a 1½-inch valve kit with a 72-inch cable; H40H72 is a 3-inch, hub-to-spigot valve with a pre-attached 72-inch cable. They are different valve assemblies, even though both use remote controls.

Cable-valve installation diagram

Valterra’s factory cable-valve installation and routing drawing (PDF) shows the cable housing, inner wire, coupler, mounting hardware and correct routing through the RV. Open the PDF for the manufacturer’s illustrated good-versus-bad cable layouts.

The manufacturer's instructions call for at least 6 inches of straight cable at the valve and handle ends, a minimum 24-inch diameter for a 180-degree bend, and no cable loops. Plan the handle location and secure the cable before cutting or fitting components. For pre-attached cable assemblies, use the instructions appropriate to that version.

The routing illustration is a guide for the manufacturer’s cable system, not a substitute for matching the exact replacement valve and existing connection type.

How to choose a replacement

  1. Identify the existing valve’s manufacturer and any moulded or stamped part number.
  2. Measure and identify the waste-pipe connections at both ends: hub, spigot or flanged valve body.
  3. Confirm the valve opening size and the space required for the gate and handle to travel.
  4. For a remote cable valve, check cable length, bend radius, accessible handle position and mounting arrangement.
  5. Drain and safely prepare the holding-tank system before opening its plumbing, then follow the applicable Valterra assembly instructions.

For hoses and outlet fittings that connect downstream from these valves, browse our RV sewer hoses, fittings and waste-valve collection. If you cannot identify the pipe connection, compare the existing valve and fittings before selecting a replacement.

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