Thermal Expansion Tanks

BackStop A series Tanks are fixed-diaphragm type, pre-pressurized thermal expansion tanks. They are designed to absorb the expansion forces and control the pressure in residential potable water systems.

Model No.	Volume (gal.)	Height	Diameter	Sys. Conn.	Wt. (lbs.)
12-A100	0.5	8.7”	5.5”	3/4”	2.6
12-A101-06	2.1	12-1/2”	8”	3/4”	4.7
12-A102	4.5	15”	11”	3/4”	8
12-A110	10	20”	11-1/2”	3/4”	13.5
12-A103	14	23-1/2”	15-1/2”	1”	20.5
12-A104	20	30-1/2”	15-1/2”	1”	27

A SERIES

Gal.	Backstop©	Amtrol	AO Smith	B&G	ELBI	Flexcon	State	Sparco	Watts	Wessels	Wilkins
2	A101	ST-5	PSC-2X	PT-5	DXT-8	WH-8	ETC-2X	TX-5	DET-5	TXC-5	XT-8
4.5	A102	ST-12	PSC-5X	PT-12	DXT-18	WH-18	ETC-5X	TX-12	DET-12	TXC-12	XT-18
14	A103	ST-30V	PSC-14	PT-30V	–	WH-50V	ETC-15	TX-30V	DET-30	TXC-30V	WXTP-50V
20	A104	ST-42V	PSC-20	PT-42V	–	WH-75V	ETC-20	TX-42V	–	–	WXTP-75V
10	A104M	ST-60V	PSC-36S	PT-60V	–	WH-120V	ETC-36	TX-60V	–	–	WXTP-120V
44	A106M	ST-80V	PSC-36S	PT-80V	–	WH-165V	–	TX-80V	–	–	WXTP-165V

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Product Sheet

Submittal Data Sheet

Flyer

Catalogue

Installation & Warranty

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Tankless Water
Heater Expansion Tanks

The new 12-TWH1 & TWH2 all stainless steel tankless water heater expansion vessel is designed for use with tankless water heaters or point of use (P.O.U.) water heaters having 2 gallons or less volume.

This new device absorbs thermal expansion and pressure surges in tankless and (P.O.U.) water heaters to protect the heat exchanger. They can also be used as a shock suppressor (water hammer arrestor) for appliances with a fixture unit capacity of 11 (“A” size). This unit is durable and corrosion resistant.

The unit is tested and approved by lAPMO, and tested at the IAPMO lab to the NSF 61 standard for potable water. The system connection is 1/2′ MPT Stainless steel and is supplied with or without an air charge valve.