20 PCS Design certified to ANSI/NSF-61 and ASSE 1061 product standard for use in potable water and hydronic heating water distribution High Quality: Made of premium-grade, lead-free brass, our ball valves delivers exceptional strength and reliability, making it an ideal choice for residential applications. Application: Our ball valves are specifically designed for circulating heating and drinking water distribution systems, the valve is approved for underground installation and use behind walls without access panels, offering maximum flexibility and convenience in installation.