Addcon Forged Steel Gate Valves are Manufactured to API 602/BS-5352. Tested to AP-998/BS-5146.Outside screw and yoke type bolted bonnet construction Body and bonnet made from high quality forgings. Easy access to stuffing box. Self-aligning gland and follower. Accurately machined gate and seat rings with mirror finished seating surfaces to assure leaktightness Wedge accurately guided throughout its travel in machined guideways in body. Rolled in body seat rings of renewable type. Back seating surfaces provided integral to bonnet.