
- (a) Describe, with the aid of a sketch, the securing arrangement for a pipe passing through a watertight bulkhead.(5)
(b) Sketch an arrangement for a watertight electric cable gland labelling ALL components.(5)
(a) Securing arrangement for a pipe passing through a watertight bulkhead (5 marks)
Description:
- When a pipe passes through a watertight bulkhead, it must not impair the watertight integrity of the bulkhead.
- A watertight gland or collar is fitted where the pipe penetrates the bulkhead.
- The pipe must be rigidly supported on both sides of the bulkhead so that no stress is transmitted to the joint.
- The collar is continuously welded to the bulkhead around the pipe, or alternatively, a bolted gland with a packing arrangement may be used for removable pipes.
- The space between the pipe and bulkhead collar is packed with oil- and water-resistant packing material, compressed by a gland flange and bolts, ensuring a tight seal.
Labelled components:
- Pipe
- Packing material (oil & water resistant)
- Gland flange and bolts
- Collar welded to bulkhead
- Pipe supports on both sides
(b) Arrangement for a watertight electric cable gland (5 marks)
Description:
- A watertight cable gland ensures that no water can pass along the cable through a bulkhead or deck while maintaining the integrity of the electrical insulation.
- The gland is made of brass or corrosion-resistant alloy and uses compression sealing rings or packing to grip and seal the cable.
- The gland body is threaded or welded into the bulkhead and is sealed with rubber or neoprene compression bushes and locknuts.
- A tapered compression ring compresses the sealing bush tightly around the cable sheath, preventing water ingress.
- The gland is designed to maintain both watertight and flameproof properties if required.
Labelled components:
- Gland body (brass or stainless steel)
- Sealing bush (neoprene or rubber)
- Compression ring
- Locknut and gland nut
- Electrical cable