1. Boiler Mountings

2. Boiler Mountings
Boiler mountings are nozzle connections, distance pieces, valves or fittings attached directly to the boiler and are always subjected to boiler pressure.

3. Boiler Mountings
Boiler valve mountings shall be opened for inspection by a U.S. Coast Guard Inspector every 5 years.
Boiler mountings, studs and bolting shall be removed, inspected and tested if necessary by a U.S. Coast Guard Marine Inspector every 10 years.

4. Boiler Mountings
Watertube boilers must be hydrostatically tested every 5 years in the presence of the U.S. Coast Guard at 1¼ times the maximum allowable working pressure (MAWP) of the boiler.
The water used for the hydrostatic test must be no less than 70 ˚F and no more than 160 ˚F.

5. Boiler Mountings
In the case the boiler has undergone major repairs. The boiler must undergo a hydrostatic test of 1-1/2 times the maximum allowable working pressure of the boiler.

6. Main Steam Stop
Main Steam Stop Valve is a valve connected directly to the boiler or, when a superheater is provided, to the superheater outlet for the purpose of connecting or isolating the boiler from the main steam line.

7. Main Steam Stop
On multiple boiler installations a stop check valve must be employed for this purpose.
If the Main Steam Stop is a 6 inch valve or larger the valve must be equipped with a bypass valve or “run around”

8. Main Steam Stop
The bypass valve is a small valve usually around ¾” to 1” which permits:
Warming up the steam line at a slow rate
Pressurizing the downstream line slowly
Equalizing the pressure on both sides of the Main Steam Stop so it is easier to open
Permits the combustion control to react to pressure changes without rapid adjustments

9. Turbo-Generator Steam Stop
The Turbo-Generator Steam Stop Valve is also connected to the superheater outlet. Its purpose is to connect or isolate the boiler from the ship service generators.
On multiple boiler installations a stop check valve must be employed for this purpose.

10. Auxiliary Steam Stop
The Auxiliary Steam Stop Valve. Is connected directly to the boiler or desuperheater outlet, if fitted for the purpose of connecting or isolating the steam to the auxiliary steam lines.
On multiple boiler installations this valve must be a stop check valve.

11. Boiler Mountings
Source: Machinery Manual Catalunya Spirit

12. Boiler Mountings
Auxiliary Steam Stop
Main Steam Stop

13. Stop Check Valve

14. Safety Valves
Safety Valves are provided for the purpose of relieving the boiler excessive steam pressure when, for some reason, the pressure builds up above the safe operating pressure.
The boiler drum is fitted with two safety valves and the superheater is provided with one.

15. Superheater Safety Valve
The superheater safety valve is placed at the superheater outlet and is set to open before the drum safety valves.
This protects the superheater from excessive temperature by insuring a steam flow through it.

16. Superheater Safety Valve

17. Main and Auxiliary Feed Stops
The Main and Auxiliary Feed Stop Valves are installed in the main and auxiliary feed lines respectively.
They are used for connecting and isolating the feed water lines to and from the boiler.

18. Main and Auxiliary Feed Stops
When the boiler is fitted with an economizer the auxiliary and main feed lines join before the economizer inlet with the stop valves fitted as close as possible to the junction point.
A check valve is then installed on the outlet of the economizer and is considered a boiler mounting in lieu of the main and auxiliary feed stop valve.

19. Main and Auxiliary Feed Stops
When the economizer is fitted with a bypass a stop check shall be installed in lieu of the check valve.
Should the economizer rupture, this check valve will close preventing the steam and water flowing back from the steam and water drum and out of the economizer.

20. Main and Auxiliary Feed Stops
Source: Machinery Manual Catalunya Spirit

21. Main and Auxiliary Feed Stops
Main Feed Line
Economizer Bypass
Auxiliary Feed Line
Source: Machinery Manual Catalunya Spirit

22. Surface and Bottom Blows
Surface and Bottom Blow Valves are connected directly to the boiler for the purpose of blowing out water, floating debris and solids.

23. Surface and Bottom Blows
The surface blow is for removing the floating impurities from the waters surface.
The bottom blow is for removing solids and sludge which has precipitated out of the boiler water.

24. Surface and Bottom Blows
Surface Blow
Bottom Blow
Source: Machinery Manual Catalunya Spirit

25. Drum Vent
The Drum Vent (Air Cock or Drum Cock) is a globe valve on the top of the steam and water drum. This valve is used to permit the escape of air when filling and lighting off a boiler. It is also used when securing or draining the boiler to prevent the formation of a vacuum.

26. Drum Vent
Drum Vent

27. Pressure Gauge Valves
Pressure Gauge Valves are globe valves mounted on the steam and water drum or other parts of the boiler used to connect or isolate the boiler pressure gauges.

28. Gauge Glass Shut Off Valves
The Gauge Glass Shut Off Valves are mounted on the top and bottom of the gauge glass, they are generally angle globe valves arranged to prevent stoppage by deposits of sediment.
The bottom shut off valve is provided with a ball check valve.
The ball of the check valve in normal operation remains on its holder.

29. Gauge Glass Shut Off Valves
In the event of gauge glass breakage the sudden rush of water through bottom connection forces the ball upward into its seat to prevent further escape of hot water.
Normally the top shut off valve of the gauge glass is not equipped in this manner.

30. Gauge Glass Shut Off Valves
Gauge glass shut off valves are generally equipped with chains to permit shut off from the operating platform.
Many boilers will also have isolation valves between the boiler and the gauge glass shut off valves.

31. Gauge Glass Shut Off Valves

32. Superheater Vent
The Superheater Vent Valve is a globe valve mounted on the superheater outlet. It permits the escape of air and steam when warming up and securing the boiler.

33. Superheater Vent
The prime purpose of the superheater vent valve is to permit steam circulation:
Through the superheater during warm up.
When securing the boiler
Or at any other time proper flow through the superheater is doubtful.

34. Superheater Drain
The Superheater Drain Valve is connected to the lowest point on the superheater and is generally a globe valve.
It is used to drain the superheater during warm up procedures
It may be used to permit drainage during boiler operation.

35. Superheater Vent and Drain

36. Superheater Vent and Drain
Superheater Drain

37. Economizer Vent Valve
The Economizer Vent Valve is a globe valve and is mounted at the highest part of the economizer.
It is used to vent all air and/or steam out, thus making sure the economizer is full of water.
It must also be opened if the economizer is to be drained to prevent the formation of a vacuum.

38. Economizer Drain
The Economizer Drain Valve is connected to the lowest of the economizer.
It is used to drain the water out of the economizer for maintenance and inspection purposes.

39. Economizer Vent and Drain
Economizer Drain
Source: Machinery Manual Catalunya Spirit