Caliber Valves Pvt. Ltd. Offers FS Gate Valves. Caliber Valves Pvt. Ltd. Is an ISO 9001-2000 certified company. The FS Gate Valves find applications in many industries. Specifications of FS Gate Valves are: Complies BS 5352 Sizes 15mm to 50mm Material Forged Steel - ASTM A105 Trim 13 percent Cr Steel / AISI 410 Type Bolted Bonnet, Outside Screw & Yoke type Rating Class 800 Ends Screwed / Socket Weld / Butt Weld