ㆍFeatures 
The tower change valve, which is the most important part of the air dryer, has completely solved the problems of either the existing ball type or butterfly type such as pressure drop due to leaking, malfunction and unstable dew point. The valve is a self-made product. 
The non-powered and non-oil feed type can move the cup valve into the shuttle valve by using inlet differential pressure as well as outlet to switch directions. Make use of the valve without leaking or repairing for 30,000 hours.

ㆍST Series 
Specifications
Size: 15A to 125A
Highest working pressure (standard): 10 ㎏/㎠
Highest working temperature: 100 ℃
Material: HOUSING — CARBON STEEL, STAINLESS STEEL
 INTERNAL — TEFLON
Warranty period: 4 years  
The powered type series can run the cylinder in the shuttle valve using Sol valve to move the disc valve and switch directions. Make use of the valve without leaking or repairing for 30,000 hours. 

ㆍPST Series 
Specifications
Size: 50A to 250A
Highest working pressure (standard): 10 ㎏/㎠
Highest working temperature: 180 ℃
Material: HOUSING — CARBON STEEL, STAINLESS STEEL
 INTERNAL — STS304
Warranty period: 4 years  

ㆍAdvantage The valve does not malfunction or leak and therefore could extend the life of the absorption agent. The long life of the shuttle valve can save the annual costs for replacement and repair.