Class 2 (2nd Engineer) MEKM 📅 Oct 2018

Exam Question

With reference to crankcase diaphragm glands.

(a) Explain why effectiveness deteriorates in service;

(b) Describe the procedure for renewal of parts so that efficiency is restored and rod scoring is avoided;

(d) Explain the functions of upper and lower sections.

Reference Answer

(a) Deterioration of Crankcase Diaphragm Gland Effectiveness:
The effectiveness of crankcase diaphragm glands diminishes over time due to wear and tear of the soft friction material comprising the gland segments. Initial installation leaves a 3-4 mm gap between segments. As wear progresses, these segments move closer, potentially butting against each other. Further wear then creates a clearance between the piston rod and the gland segments, permitting the passage of scavenge air, oil, sludge, and other contaminants. This leakage compromises the gland's sealing function.
(b) Procedure for renewal of Stuffing box parts:
The diaphragm gland is typically overhauled simultaneously with the piston during piston withdrawal from the engine.

Full answer on MeoMock — surveyor-grade reference answers for 7,000+ written exam questions.

View plans Browse library

← Browse more questions

Prepare on Android — MeoMock on Google Play