Spesification
Model : JSQ-111
Main Material : Stainless Steel
Release Depth : 2-4 m
Tensile Strength : 15 Kn
Description
1. Product Introduction
Hydrostatic Release Units (HRU) is a device used for releasing inflatable liferafts fastened on ships. When a ship sinks, HRU operates automatically within a depth of 2-4 m and then liferaft functions properly.
This unit, which proved to be an ideal set, complies with 1996 amendments of 1974 SOLAS.
2. Installation Method
Hydrostatic Release Units (HRU) shoult be installed as follows:
– It is to be installed only when given a satisfactory Performance license, approved by register of shipping or checked by authorize liferaft service station.
– The unit is vertically secured to the horizontal rod of the liferafy with bolts. Its marking should face inboard, the lifting hook (6) up ward and HRU should be firmly secured to the horizontal rod.
– Connect the hook lind (1) with the connecting link, the hook (2) with the shackle. The Painter (3) and weak rope (4) are connected with the shackle, and the connection bet with them should be secure (See Fig 1)
– When installing the split pin (8) on the connecting lnk (9), the folding angle should be less than 30 Degree so as to be easily pulled out when necessarily.
– The Band used for securing liferaft container should be fastened tightly with the turnbuckle
3. Release Mode
The unit can be operated manually and automatically
– Manual Operation
Pulling the split pin (8) out and pushing the small link on the connecting link upward, the securing band will be loosed automatically and the liferaft thrown outboard. (See Fig 1)
– Automatical Operation
When the ship sinks to the sea, sea water enters the storage chamber of the unit through its inlet, water pressure on the diaphragm in turn presses the spring, then forces the short shaft (5) moving in ward. Meanwhile, the submerged container produces buoyance which makes the hook (6) turn around the shaft in turn the safety hook (7) then makes the hook links lip off. Under the action of buoyance, the container rises to water surface and makes the liferaft inflate. When the ship sinks to a certain depth, the weak rope will be snapped, thus the liferaft separated from the ship (See Fig. 2, See Fig 3, See Fig 4)
4. Automatic Releasing Process
In Case of rapid sinking of the ship, there is no time for manual releasing, so when the sinking ship submerges at a certain depth the liferaft can be released automatically by HRU the process is as Follows: (See Fig 3A-3D)
– The liferaft sinks together with the ship (See Fig. 3A)
– When ship sinks with in a depth of less than 4m, HRU immediately looses the securing band on th liferaft, then the liferaft begins to rise. (See Fig 3B)
– With the continual sinking of the ship and rising of the liferaft. The line is gradually drawed out and in turn the inflation system is operated, then the liferaft will be completed its inflation (See Fig 3C)
– Under action of buoyance produced by the inflated liferaft, the weak rope connecting with HRU is snapped, the liferaft then is separated from the ship, and the people falling in the sea can embark on the liferaft (See Fig 3D)
5. Maintenance
– Ordinarily HRU can’t be released manually at random or pushed the short shaft by any cone.
– In Order to ensure the inlet not to be clogged, HRU should not be painted.
– Inspect the wear and deterioration of the weak rope periodically, if anything discovered unsuited to the present need, replacement of a new one should be in time, in any case, during the annual overhaul the old rope should be replaced with new one.
– The connection between the painter and HRU should be inspected periodically
– Tension of the band for securing the container must be inspected regulaily. If any where found loosing or not tight enough, adjustment should be made in time.
– Like the liferaft, HRU should have an annual overhaul and should be overhauled by the trained at the authorized liferaft service station.
– The diaphragm is not allowed to be allowed to be touched by any sharp object. If anywhere of the diaphragm found stickness, brittleness, crack or any abnormal phenomena, replacement should be made in time.
– If HRU has been operated owing to some unused reasons, it ought to be reset. The resetting method is using a cone (about 3mm dia) to push the short shaft (5) moving inward through the resetting hole, then push safety hook (7) and lift hook (6) to their original positions separately (See. Fig 4)
