How to properly measure the pulleys/sheaves on the pump and engine

Christopher

Christopher

Moderator
Hello Russ, I am thinking of changing out the worn Hawk pump on my Hotsy hot water skid with a General TSF 2021 pump. The engine on the skid is a Vanguard 21hp that I have used for 9 years now and it is still running great.

I am not sure if the pulley/sheave will come off the Hawk pump easily so I was thinking of just getting a new one for the TSF2021 pump.

I don't know the proper way of measuring the pulley/sheave so I can measure both and then ask you, Paul or Jerry what size I will need for the pump when looking at the engine pulley sheave.

Do you measure from one side to the other or put a string around it where the belt rides and then measure that string or what should I do?


If I am thinking correctly, once the pulley/sheave part is done then I will just take the trailer to the shop and have them change out the pumps, probably will have to drill new holes for the pump.

I am thinking that they might have to adjust the fuel pressure and maybe the air bands so that the added flow will get hot.

What else will need to be done?

I am hoping that this will work good so then I will finally have an 8gpm hot water rig.

Thanks Russ.
 
The outside diameter (measuring across the flat face of the pulleys) is what you need for proper sizing. To find "X" for the pump pulley, the formula is:
(eng. RPM X eng. pulley diameter) / pump RPM = X

If the burner on the Hotsy is 12 volt, you're kind of stuck with the heat you've got. Monkeying with the fuel pressure and air mix isn't going to net you much more heat.

I would recommend you look hard at the AR XW series pumps before deciding on the TSF.
http://www.arnorthamerica.com/xwpumps/xwa-m8g35npg1.html

When you get ready to buy, give me a call.
 
I already have the TSF2021 General Pump Russ.

Are you saying that it will not work or is not a good idea?

I was going to use this pump to replace the Hawk pump since I already had it here.

Yes, the Hotsy is 12 volt so you are saying that if the water does not get hot enough with the added flow, I am stuck with it?

Thanks Russ.
 
Russ, do you think that the 8gpm pump on that Hotsy will heat the water hot enough for removing gum?

Thanks.
 
I usually keep the burner thermostat set at 180 degrees and it does ok at that temp. I can turn it up more when needed but most of the time 180 will do the job.

I am thinking now that maybe I should just keep it the way it is and use the 8gpm pump on something else since I need hotter water than 140 degrees for gum cleaning.

Thanks Russ.
 
8gpm x 3400psi x .0007 = 19hpContinuous
..21hp rated x 75%= 15.75hpC.
.. you need a 25+hp rated gasoline engine to get 21hpContinuous..
.. .. try another engine and heater
sorry :{/

or..
you could run the pump at 6.5gpm, enjoy a little better heat, and have 3400psi
.. Does that turn lemon into lemonaid for you ??
:{)
 
If you run a trapped pressure unloader, set max pressure on unloader so it won't go higher than the pump is rated and run a smaller tip and you will get the heat you need. The extra water will bypass and you will only be getting X amount of water at the pressure you set the unloader at for the tip you use. You can look at a tip chart to determine what tip to use but your tips for your current pump will probably work unless its rated at a higher pressure.
 
Also if you don't really need the 8 gpm, you can go bigger with the pump pulley and slow it down so it pumps around 6.5 gpm and have full pressure, and extend the life of the pump a lot! Also you won't be so hard on the engine. It will be a strain running it wide open for sure, ESP on a 9 year old engine!

The General TSF pumps are very good pumps! IMO. I am not real familiar with the AR Russ suggested but have a lot of experience with the tsf.not saying that AR is not better, I have no idea, but the general is a good one also. Most of my experience is with the TSF2021 and I have had a LOT less trouble out of it than I did with the old TS 2021 that everyone loves so much! Lol
 
On your heater, you could possibly put larger fuel nozzle in and adjust the air and get a lil more heat but it really depends on your burner. If the fuel pump doesnt pump enough fuel, that could actually cause fuel pressure problems etc. Also if its a smaller size heater, you might not get enough air through it to efficiently burn the fuel. If it is a smaller coil you may not be able to get the water heated before it exits the coil and would just be wasting fuel trying to heat it.

Best bet is a bigger heater if you wanna heat 8gpm unless you know for sure that your coil is just as big or bigger than what usually comes on 8gpm machines. If it is you could order a complete burner assembly for an 8gpm or larger machine and save a few bucks over a whole new heater.

Just a few ideas that might save you a few $s.
 
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