Technology and Operations
This forum is for discussing technological & operational matters pertaining to U-boats.
Compressed Air System Part V
Posted by:
Scott
()
Date: November 08, 2001 09:45PM
This system begins with a lead from the high pressure manifold which branches, each branch passing through a 205 to 12 atmosphere (2920 psi to 171 psi) reducing valve and is then brought to the low pressure manifold in the control room. In addition to this source of supply there is a separate line connecting the low pressure manifold to the low pressure torpedo air manifold in the forward and after torpedo rooms which, in turn have connections to the high pressure air system.
The manifold has one valve for each of the following:
a) Vent valve operating.
b) Torpedo low pressure manifold forward (which also can serve as supply).
c) Torpedo low pressure manifold aft (which also serves as supply) from which branches leads to the engine clutch operating gear and two sea-cheat blow connections.
d) Diving plane clutch operating gear.
e) RDF mast hoist.
f) Radar mast and radio antenna hoist.
g) Bilge pump sea-chest blow connection.
h) Gyro compress cooling.
i) Pneumatic tools.
j) Horn.
All the valves on the manifold are normal stop valves except the one to the tool connection, which is a regulating valve.
The pressure reducing valves are regular Draeger valves. They operate on a conterbalanced spring and diaphragm basis. One spring on the high pressure side of the line pushes a gasketed valve piston onto a seat. Another spring, separated from the low pressure chamber of the valve by a membrane, is chamber, which last, bears on the center of the valve piston. If ther is no compression of the low pressure spring, the valve is closed by the high pressure spring pushing the piston onto its seat. By compressing the low pressure spring, pressure offsetting that of the high pressure spring in placed on the valve piston, which is forced off its seat, therby, admitting air to the low pressure chamber.This deforming the diaphragm membrane and compressing the low pressure spring futher, taking the counter pressure off the center of the valve piston which is reseated by pressure from the high pressure spring, therby, stopping the flow of air. As the air pressure in the low pressure chamber falls, the low pressure spring takes charge and pushes the pin against the valve piston sufficiently to unseat it. The valve is basically a commercial type unit and come in a number of different sizes, with varying arrangements of springs, but the principle on which all operate is the same. It relies for satisfactory operation on proper spring balance betwwen a very large spring and a very small spring. The large one, on the low pressure side, is readily accessible, but fatigue of the small spring has the effect of introducing increasingly higher pressures into the low pressure side of the valve, and the valve must be disassembled to do any work on the small spring. The amount of maintenance probably accounts for the two reducing valves in parallel.
The line to the ballast tank vent operating gear leads via a main valve and another pressure gauge, to three four-way cocks in parallel, in the control room. Each of these cocks connects, by way of two lines and a second four-way cock, to an air cylinder in which is the pistion for opening and closing one group of vent valves.
One of the three cocks first mentioned above control the air to separate operating gear for MBT 1 and FBT 3, one controls the air to a common unit actuating vents for FBT 4 and MBT 5, and one controls two units for vents on FBT 6 and 7 and 8.
The two torpedo low pressure manifolds are each provided with a connection for pneumatic tools, a line to the marker buoy stowage, and a line to the group of valves which control the flooding, blowing and draining of the torpedo tubes. This last group of valves, for each tube, conisists of a stop valve, a relief valve and pressure gauge, a four way cock whichadmits air to the torpedo tube on the WRT tank while venting the other one of the pari, and a three-way cock to permit selective venting of eigher or both ends of the torpedo tube. There is also an individual cock in the vent line of each WRT tank, and a common three-way cock which permits selective use of either WRT tank by any torpedo tube.
The sea chest blow arrangement merely provide a connection to the sea side of certain sea valves for the purpose of clearing clogged strainers. They are all operated from the adjacent compartment.
The connection to the engine clutch operating gear leads by way of a stop valve and a pressure gauge, to a four-way cock at each engine. The cock has one line to each of two air-oil cylinders, and can introduce air pressure on one of them while venting the other, therby forcing oil into one end or the other of a cylinder in which is a pistion is a pistion which operates the main engine shaft clutch.
The line to the low and stern diving plane clutches branches at the diving station, with a separate valve for each set of planes, and runs fore and aft to the torpedo rooms where it conects to the clutch operating gear.
The lines to the mast connect to the air cylinders for raising and lowering the mast.
The line to the horn leads, by way of a lever-operated back-up valve and a stop valve at the hull, to the horn.
The manifold has one valve for each of the following:
a) Vent valve operating.
b) Torpedo low pressure manifold forward (which also can serve as supply).
c) Torpedo low pressure manifold aft (which also serves as supply) from which branches leads to the engine clutch operating gear and two sea-cheat blow connections.
d) Diving plane clutch operating gear.
e) RDF mast hoist.
f) Radar mast and radio antenna hoist.
g) Bilge pump sea-chest blow connection.
h) Gyro compress cooling.
i) Pneumatic tools.
j) Horn.
All the valves on the manifold are normal stop valves except the one to the tool connection, which is a regulating valve.
The pressure reducing valves are regular Draeger valves. They operate on a conterbalanced spring and diaphragm basis. One spring on the high pressure side of the line pushes a gasketed valve piston onto a seat. Another spring, separated from the low pressure chamber of the valve by a membrane, is chamber, which last, bears on the center of the valve piston. If ther is no compression of the low pressure spring, the valve is closed by the high pressure spring pushing the piston onto its seat. By compressing the low pressure spring, pressure offsetting that of the high pressure spring in placed on the valve piston, which is forced off its seat, therby, admitting air to the low pressure chamber.This deforming the diaphragm membrane and compressing the low pressure spring futher, taking the counter pressure off the center of the valve piston which is reseated by pressure from the high pressure spring, therby, stopping the flow of air. As the air pressure in the low pressure chamber falls, the low pressure spring takes charge and pushes the pin against the valve piston sufficiently to unseat it. The valve is basically a commercial type unit and come in a number of different sizes, with varying arrangements of springs, but the principle on which all operate is the same. It relies for satisfactory operation on proper spring balance betwwen a very large spring and a very small spring. The large one, on the low pressure side, is readily accessible, but fatigue of the small spring has the effect of introducing increasingly higher pressures into the low pressure side of the valve, and the valve must be disassembled to do any work on the small spring. The amount of maintenance probably accounts for the two reducing valves in parallel.
The line to the ballast tank vent operating gear leads via a main valve and another pressure gauge, to three four-way cocks in parallel, in the control room. Each of these cocks connects, by way of two lines and a second four-way cock, to an air cylinder in which is the pistion for opening and closing one group of vent valves.
One of the three cocks first mentioned above control the air to separate operating gear for MBT 1 and FBT 3, one controls the air to a common unit actuating vents for FBT 4 and MBT 5, and one controls two units for vents on FBT 6 and 7 and 8.
The two torpedo low pressure manifolds are each provided with a connection for pneumatic tools, a line to the marker buoy stowage, and a line to the group of valves which control the flooding, blowing and draining of the torpedo tubes. This last group of valves, for each tube, conisists of a stop valve, a relief valve and pressure gauge, a four way cock whichadmits air to the torpedo tube on the WRT tank while venting the other one of the pari, and a three-way cock to permit selective venting of eigher or both ends of the torpedo tube. There is also an individual cock in the vent line of each WRT tank, and a common three-way cock which permits selective use of either WRT tank by any torpedo tube.
The sea chest blow arrangement merely provide a connection to the sea side of certain sea valves for the purpose of clearing clogged strainers. They are all operated from the adjacent compartment.
The connection to the engine clutch operating gear leads by way of a stop valve and a pressure gauge, to a four-way cock at each engine. The cock has one line to each of two air-oil cylinders, and can introduce air pressure on one of them while venting the other, therby forcing oil into one end or the other of a cylinder in which is a pistion is a pistion which operates the main engine shaft clutch.
The line to the low and stern diving plane clutches branches at the diving station, with a separate valve for each set of planes, and runs fore and aft to the torpedo rooms where it conects to the clutch operating gear.
The lines to the mast connect to the air cylinders for raising and lowering the mast.
The line to the horn leads, by way of a lever-operated back-up valve and a stop valve at the hull, to the horn.
| Subject | Written By | Posted |
|---|---|---|
Compressed Air System Part V
|
Scott | 11/08/2001 09:45PM |