Plumbing parts by job: name, location and purpose

Kitchen sink or basin

• Strainer or drain body: connects the bowl to drainage and catches solids.
• Approved gasket and sealant: seals under the flange.
• Tailpiece: descends toward the trap.
• Slip-joint washers and nuts: aligned removable joints.
• P-trap: holds a water seal against sewer gas.
• Trap adapter: joins removable tubing to the fixed system.
• Trap arm: reaches the wall drain with correct slope.
• Fixture stops: isolate hot and cold water.
• Listed supply connectors: join stops to faucet without strain.
• Escutcheons: finish openings but are not primary waterproofing.

Toilet

• Closet flange: anchors the toilet and joins the drain.
• Closet bolts: clamp the bowl to the flange.
• Wax ring or compatible seal: seals outlet to flange.
• Non-compressible shims: prevent rocking.
• Stop and supply connector: isolate and feed the tank.
• Fill valve: controls tank level.
• Flapper or flush valve: releases flush water.
• Overflow tube: prevents tank overflow.
• Perimeter sealant per local rule: stabilizes and manages leak visibility as required.

Dishwasher

• Dedicated stop: isolation.
• Listed water connector: pressurized supply.
• Drain connection to a designed fitting: discharge.
• High loop or air gap where required: limits dirty-water backflow.
• Clamps: prevent disconnection.
• Pan or detector: reveals leakage.
• Receptacle/disconnect and electrical protection: per code and manufacturer.

Washing machine

• Hot/cold valves: quick isolation.
• Listed hoses: pressurized supply.
• Outlet box: organizes valves and drain.
• Standpipe and trap: receive flow and block sewer gas.
• Hose support: prevents escape or excessive insertion.
• Pan, drain or detector: reduces damage where appropriate.
• Water-hammer arrestors only when required and correctly located.

Water heater

• Water shutoff, suitable fittings, T&P valve, discharge pipe, pan, drain, expansion tank, mixing valve and energy supply form a system. Each addresses isolation, corrosion, pressure, leakage, expansion, scalding or energy; none should be improvised.

Why dimensions matter

Diameter, material, thread, joint type, insertion depth, slope, orientation and listing must match. A part that appears to thread on may be incompatible for pressure, temperature, gas, potable water or drainage. Bring photos, measurements and the old part to the supplier, but confirm with manufacturer and local rules.