Sash support help

A quick learner from Tonawanda, NY says:
June 30, 2013
My broken sash support has 21TGX BSI stamped on it. It is regular channel measuring 9/16 in wide, 1/2 deep by 22 long. I do not know what the replacement part number is that I should buy. It looks like your S770-22 but I do not know the weight range. Any help would be appreciated.
User submitted photos of a window balance.
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Tom from SWISCO responded:
July 1, 2013
Great, knowing that our S770-22 is a match helps. Can you tell me the weight of your sash? That will help us determine the best possible option among those listed for the S770-22.
A quick learner from Tonawanda, ny says:
July 2, 2013
The window by itself weighs 20.2 lbs
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Paul from SWISCO responded:
July 2, 2013
Great. In that case, I recommend the 22C option. *Two balances with this option can carry a window sash weight range of 16 through 21 pounds.

*This information is based on 2 balances per sash. Balances are designed assuming friction in the jamb weather-strip will carry a portion of the sash weight. Suggested sash weights are approximate.
A quick learner says:
July 2, 2013
Thank you very much for the help. I really appreciate it.
22" Series 770 Balance
22" Series 770 Balance
S770-22
$12.27
How to replace a tilt-window channel balance.
How to replace a tilt-window channel balance.
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