Marine Type Approvals held for these valves: American Bureau of Shipping, Bureau Veritas, DNV, Germanischer Lloyd, Lloyds Register. Overflow and control valves made of gunmetal with stainless steel spring. Suitable for liquids, steam and gaseous media. Adjustable under operating conditions without medium escaping in the atmosphere. Gastight version of spring housing. Available models: 617tGFO gastight version for gases and liquids, without lifting device. Available seals: NBR, FKM, PTFE. Ranges of adjustment: 0.5 – 2.5 bar, 2.0 – 8.0 bar, 2.0 – 12 bar, 12 – 20 bar (with PTFE seal). Valves can be delivered unset within a pressure range or set and sealed at the factory. All models are also available in Stainless Steel: series 417. Series 617 (Gunmetal) Model 617tGFO gastight version for gases and liquids, without lifting device