600 and 150 psi Auxiliary Steam, upper level
Patriot State was the training ship of the Massachusetts Maritime Academy from 1986 to 1998.
There are two 600 to 150 psi reducing stations aboard. Both have stop valves before and after and a by-pass around them, with a strainer installed on the inlet side.
One station, known as the "dry" 150 psi system, supplies dry steam to the main, auxiliary and evaporator air ejectors. The dry 150 system is supplied with a relief valve set at 165 p.s.i., and has a valved cross connection from the other reducing station. This station is supplied through a 1 inch line from the 600 psi desuperheated main.
The other 150 psi station, known as the "wet" 150 psi system, supplies the general service pump, and lube oil standby pump, the Alpha-Laval Evaporator, the whistle, sealing steam for the main feed pump, gland sealing steam for the main engine, boiler lancing, atomizing steam, the 65 psi reducing station, the 35 psi reducing station for 3 hold heating, and the 150 to 15 psi auxiliary exhaust make-up station. This station is supplied through a 3 inch line from the auxiliary steam main and is equipped with a 4 inch external desuperheater.
600 and 150 psi Auxiliary Steam, upper level
600 and 150 psi Auxiliary Steam, lower level
The Butterworth heater is supplied through a 3 inch branch line from the auxiliary steam main to a 600/125 psi reducing station, with a stop valve before and after and a by-pass valve around the thermostatic reducing valve. A strainer is installed on the inlet side of this reducing valve. The reducing valve has a connection on the salt water outlet line of the heater and the temperature of the salt water in the Butterworth heater is maintained at 180° F. A relief valve set at 215 psi and a pressure gauge are installed at the steam inlet of the heater.
The Butterworth heater was used to provide hot water for cargo tank cleaning, and is no longer needed.
The 65 psi contaminated system provides steam to the following equipment and services which have the potential to contaminate the steam or condensate with oil:
Condensate returns from these consumers return to the contaminated drain tank.
This system can be supplied with steam from the 150 to 65 psi reducing station or with steam generated by the contaminated evaporator.
When the contaminated evaporator is used in conjunction with the contaminated drain tank and the contaminated feed pumps, a complete, closed steam system is created which precludes the possibility of contaminated condensate returning to the boiler.
The 65 psi system is protected by a relief valve is set at 80 psi, and has a local pressure gauge and a gauge on main gauge board.
65 psi Auxiliary Steam, lower level
The 35 psi auxiliary steam system provides steam for ship's heating except for three hold, galley use, and for the hot water heater located on B-deck,
35 psi steam is provided from the 65 psi contaminated system through a pressure reducing valve. The piping downstream of this valve is protected against excessive pressure by a relief valve set at 45 psi.
65 and 35 psi Auxiliary Steam, upper level
The 600 to 135, 135 to 35, and 35 to 5 psi reducing stations located in the lower port engine room were installed when the ship was converted to a training ship in 1985 to provide steam for the number three evaporator and for hot water and quarters heating for the cadet berthing area. The hot water heater is no longer used, because the original ships hot water heater is able to meet the demand of the entire ship. The 35 psi reducing station was moved and it is now supplied by the 150 psi system, and the Alpha-Laval Evaporator supplies our additional water requirements.
600, 135, 35, and 5 psi Auxiliary Steam, lower level
Contaminated Drain System
The auxiliary exhaust system receives exhaust steam primarily from the main feed pump turbines, and any operating steam reciprocating pumps. This system also receives make-up steam from the reefer induction system and from the 150/15 psi reducing station.
The primary service of the auxiliary exhaust system is heating condensate in the deaerating feedwater heater and feed heating in evaporators number one and two.
To summarize, steam is supplied to the auxiliary exhaust system from:
and the auxiliary exhaust system supplies steam to:
If the auxiliary exhaust pressure falls below 15 psi due to excessive demand or insufficient supply, make-up steam is supplied via 150/15 psi reducting station. Make-up steam can also be supplied from the reefer induction system.
If auxiliary exhaust pressure rises to 25 psi, an automatic dump valve opens, dumping excess steam to the auxiliary condenser.
If the auxiliary exhaust pressure rises above 35 psi, a relief valve opens and dumps excess steam to the atmosphere.
Induction System, 15 psi Auxiliary Exhaust, 150 psi Auxiliary Steam, upper level
Induction System, 15 psi Auxiliary Exhaust, lower level
Direct comments to William Haynes whaynes@maritime.edu
Mon, Jul 1, 1996
TSPS Engineering Manual ©1995 Massachusetts Maritime Academy