Hotel heating questions..

[josh]

Have been working in a hotel (27 rooms with ensuites) changing staff toilets and adding a radiator and would like to have more of an understanding of some of the bits in the plant room.
The plant room has 4 boilers (potterton osprey 2) with 5 heating zones and the older bigger grundfos pump in pic 5 serving 4 open vent cylinders, one being horizontal.

Would be grateful if anyone had the time to explain their function and how they work a bit.
have put pictures up of the bits in a new set on my flickr:


Hotel heating questions? - a set on Flickr


pic 1: The middle part of this valve just drops to the floor, is the only purpose of this for draining down or does it do something else aswell?

pics 2 + 3: These valves i have seen elsewhere but the middle part of the valve goes to the return and have a balancing valve on it, how exactly do they work and what do you set the balancing valves to that come from the middle part of the valve? The minimum flow rate of the boilers?

pic 4: I know these are temp sensors and are on every flow but how are they operating/controlling within the system? there is also one on the main flow from the boilers, again how is that linked in and working to control the boilers?

pic 6: I know this is for shutting of the gas supply should a fire break the fusible link and if you did an install with a link now you'd have a solenoid instead to shut of the gas supply, right or not?
If the link was broke, for example by an employee somehow, could you reset it simply by puling the lever back by putting the link wire correctly back in place under tension?

pic 7: I know these are for balancing purposes on the returns, when on the returns from a heating circuit are they just set to the maximum flow rate required by that circuit? and again if they are on a single heat emitter, say a fan heater with a coil they are set to the maximum flow rate required by that product?

Finally pic 8: Are these just lockshields? A few about but the one in the pic is on the secondary tapping on the cylinders from the bronze pump with a lever valve been cut in before it.



I don't expect them all to be answered as i'v asked a lot but just a bit more information would be good just for my own knowledge really, i'm only 22 and still have a hell of a lot to learn.
Thought i'd put it in the private gas safe section to keep it sort of in house if you know what i mean.

Thanks again for any help.
Josh.

 

[Scott_D]

Pic 1 - looks like a drain and vent valve, normalyl in the vent position but can be set to drain for maintenance
Pic 2+3 - 3 post valves, when a circuit is up to temp or not needed the valve head will move a plunger and change the port that’s open/closed.Controlled by the BMS
Constant temp heating circuits will often have a 3 port or bypass at the air handling unit, plate heat exchanger, hot water cylinder etc
Variable temp heating circuit will have the 3 port in theplant room for radiators etc
Pic 4 - Flow or temp sensors, the info can be used by the BMS to monitor the system, open closed 3 ports etc.
Pic 5+6 - As you have said, it can be reset if the pin is released by the emergency shut off button.
The valve handle is usually weighted and the valve will close if the wire is broken or released
A solenoid is the modern way and is often linked to the firealarm system
Pic 7 - Regulating valve to throttle down the flow of water,used to balance a system so one circuit doesn’t rob another.
Pic 8 - looks more like a gate valve with the handle/splindlebroken off. Maybe why there is a new lever valve after it.

 

[josh]

Thanks Scott for your time to have a look and answer all of them, much appreciated.

 

[Dotty]

Beat me to it Scott.

 

[Scott_D]

Beat me to it Scott.

Caught you napping

Thanks Scott for your time to have a look and answer all of them, much appreciated.

No problem, I like the drain off in Pic 3

 

[josh]

Always handy upside down, guessing it was fitted as a vent?

So that 3 post valve in pic 3 serving a cylinder, when the cyl stat is satisfied the valve will close to the cyl and open the center of the valve sending it straight to the return, why not just use a two port valve instead?

 

[Dotty]

Because it modulates the primary temperature and therefore maintains a steady dhw temperature for the residents.

 

[josh]

Another question, in pic 9 there is a steel pipe that overhangs the boilers that is open with a sort of terminal fitting on the end of it.

The boilers air is provided by a mechanical fan, guessing that must be interlocked with the boilers should it fail. Does this steel pipe have anything to do with that? Any guess what it is, can't see where it goes, just through the wall and disapears. (plant room is in center of hotel on ground floor)

 

[josh]

Because it modulates the primary temperature and therefore maintains a steady dhw temperature for the residents.

ahh i see, so not just get it to temp using the same flow temp like in a domestic installation.
Thanks croppie for that.

Don't know if you remember like a year ago or more talking about welding pipe, currently on a evening welding course learning arc, certainly a knack to it, my welds currently look blobby, lol.

 

[IDCHAPPY]

Sure pic 9 aint part of a sprinkler system or something? it's hard to tell without a good pic of the end of it