Stuffing Box

Mechanical Seal Box

The mechanical seal box, also called the seal chamber or gland assembly, houses and protects the mechanical seal in drilling mud centrifugal sand pumps. It is built for abrasive, high-pressure, and corrosive service conditions. TR's seal box is a direct interchange for NOV Mission MAGNUM CENTRIFUGAL (P/N 22223-01-30) and 2500 SUPREME (P/N H22223-01-30) sand pumps, with identical mounting dimensions and materials to OEM standard.

Key Structural Features

1. Seal chamber: Forms an enclosed space and stable pressure environment, accommodating flush and barrier fluids.

2. Gland and fasteners: Locks the stationary ring in place and keeps spring compression within manufacturer tolerances.

3. Cooling and flush ports: Connect to external piping to provide cooling, lubrication, and impurity flushing for the sealing faces (API standard flushing plans).

4. Anti-rotation pin: Prevents the stationary ring from turning with the shaft, protecting the seal faces from accelerated wear.

5. Auxiliary seals: Provide static sealing between the gland and the pump casing or shaft sleeve.

Operating Principle

The mechanical seal assembly holds the mating faces of the rotating ring (which turns with the shaft) and the stationary ring (fixed to the housing) . Spring force and process pressure hold the two lapped faces in close contact, forming a thin fluid film that lubricates the faces and blocks mud and sand ingress. External flushing continuously removes heat and abrasive particles, extending seal service life.

Operating Conditions

Typical applications: NOV Mission centrifugal pumps, mud pumps for drilling fluid circulation (desanding, desilting, and mixing). Handles abrasive, high‑viscosity, solids‑laden media.

Operating Range:  –20°C to 120°C, medium‑to‑high pressure, up to 1750 RPM.

Key Advantages

1. Precise dimensional match reduces installation errors.

2. Wear‑resistant materials and flush design minimize leaks and downtime.

3. Complete assembly can be removed and replaced as a unit for quick maintenance.