The Model AT-1000 Freeze Valve was developed to indicate the presence or absence of moisture in Liquefied Propane Gas (LPG). The AT-1000 is designed to be compliant to the Valve Freeze Method (ASTM D2713-15). The Valve Freeze Method was first published for information only by the American Society for Testing Materials in the “ASTM 1963 Standards: Volume 18”. Since then, it remains the only practical field test device to determine if excess moisture is present in LPG.

The Valve Freeze Test method provides a relative measure of the tendency of Propane (LPG) containing moisture to freeze in pressure reducing regulators which may interrupt the normal flow of gas. Antifreeze agents will interfere with this test method and can indicate that the product is drier than it really is. However, the relative test times of LPG with antifreeze agents may still provide an indication of the tendency of these products to cause freezing in systems.

Water in LPG can cause multiple issues, the primary concern being the freezing of pressure regulators mentioned above and a hidden problem with moisture that drops out of solution to form a water rich layer at the bottom of the tank that can freeze in colder environments. Over time, the addition of Antifreeze agents (e.g. methanol) may increase the corrosiveness of this water rich layer, leading to shortened service life of the tank and cause general degradation of elastomers (seals, hoses, etc).

Preventing water from entering the transport and storage system is difficult, so testing of the LPG fer ASTM D2713-15 is critical to ensuring that the LPG delivered to the end user is dry.

The Viatran Model AT-1000 is also used with other harmonized standards including IP 395/98, ISO 13758:1996 (2018) and JLPGA-S-10T.