Usage:
CONFIDENTIAL
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TECHNICAL INFORMATION BULLETIN |
JANUARY 31, 2001 |
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EXCAVATORS |
E70 (3BG, 3CG), E70B (7YF, 5TG, 6AK), E110 (3FG, 3GG), E110B (8MF, 9HF, 5GK), E120 (1LF, 1MF), E120B (6JF, 7NF, 4XK), E140 (1NF, 1PF), E180 (1RF, 2BF, 4EF, 4HF), E200B (6KF, 7DF, 4SG, 5EG), E240 (2HF, 4JF, 4MF, 1FG), E240B (5WG, 6MG, 8SF, 9PF), E240C (8MK, 9NK, 9PK, 2RL), E300 (2CF, 4NF, 4SF, 1KG), E300B (1WJ, 2HJ, 3FJ, 1GK), |
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Component Code(s) 7056 |
SUBJECT: RELEASING PRESSURE GAS IN THE COUNTERWEIGHT SHELL
PROBLEM:
Small amounts of hydrogen gas are generated during the normal curing process in the counterweight shell. The chemical reaction between the "ironsand", cement, and water create the gas. If counterweights are improperly vented, the free hydrogen gas cannot escape to the atmosphere. Improperly vented counterweights can build up pressure inside. Internal explosions can occur during counterweight modifications when flame cutting, welding, or grinding.
SOLUTION:
Make sure that the counterweight is properly vented before attempting any modifications to the counterweight shell. Use pressure air blown through the shell to purge the gas before making any modifications. If the counterweight is improperly vented, it may be necessary to make temporary vents. The temporary vents can be used to purge the shell and remove the gas. Reference Special Instruction SEHS9267 for the procedure to create temporary vent holes in the counterweight shell.
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ALL RIGHTS RESERVED