EMERSON. YARWAY BLOW-OFF VALVES SEATLESS, HARDSEAT AND UNIT TANDEMDesigned for blow-off service in boiler systems with pressures of 3206 psig. • Designed according ASME section 1, ASME B31.1, ASME B16.34. • For boiler systems up to 3206 psig. • Rugged construction to withstand high pressure and high velocities. • Excellent resistance to cleaning acids and wear caused by precipitated solids. Seatless valves • No Seat - will not score or plug with dirt - will not leak • Live-loaded packing - will not leak after packing • Slow opening -will not rapidly drain boiler drum Unit tandem valves • Combination of hardseat and seatless valves in a single body - eliminates pipe joints - reduces potential leaks - fits into a confined space Hardseat valves • Stellite seat faces - resists wear - provides long service life Blow-off service in boiler systems to remove Size range: NPS 1, 1%, IV2, 2, 2V2 dirt, sediment and scale as well as maintain [DN 25, 32, 40, 50, 65] boiler level surge. Pressure Rating: Up to 3206 psi Connection: Flanged, Socketweld, Buttweld Materials: Cast Iron, Carbon Steel Emerson.com/FinalControl © 2017 Emerson. All Rights Reserved VCTDS-00404-EN 15/06

GENERAL DESCRIPTION TYPE B SEATLESS BLOW-OFF VALVE Basic requirements for the design and use of blow-off valves are established by the ASME Power Boiler Code, Section l. The general form of a valve, the materials of its construction, allowable boiler pressures, and the installation of the valve are all determined by the code. Yarway blow-off valves are designed in conformance with all code requirements (ASME Section l, ASME B31.1, ASME B16.34). Because the primary purpose of a blow-off valve is removal of dirt, sediment and scale, the boiler code requires that valves which have dams or pockets...

Flange and drilling data common to all Yarway valve designs are shown below. AH dimensions are consistent with ASME standards and supplied as listed unless otherwise specified. NOTES: 1. Includes VC raised face 250-400 psi valves, W" raised face 600-2500 psi 2.600 psi only, no 1" 400 psi valve available. 3. Bolt holes straddle center lines.

YARWAY BLOW-OFF VALVES SEATLESS, HARDSEAT AND UNIT TANDEM SEATLESS VALVES FOR PRESSURES TO 935 PSI - CLASS 250 TO 600 The seatless blow-off valve is a sliding plunger type, opened and closed by means of a handwheel and non-rising stem, and sealed against leakage by packing rings above and below the ports. This valve is provided with heavy coil compression springs under the yoke nuts. Designed to help prevent leaking when the valve is open, yoke nuts are screwed down evenly and tightly placing compression on the springs and the packing rings. Ample flow area is provided in the hollow plunger;...

YARWAY BLOW-OFF VALVES SEATLESS, HARDSEAT AND UNIT TANDEM Standard options Acid wash trim: 1. Standard upper gland is replaced with nickel plated steel upper gland. 2. Standard lower gland is replaced with Ni-resist lower gland. 3. Standard plunger is replaced with nickel plated nitrattoy plunger. Stop screw with lubrication fitting. Caution ptate for tandem sets. Special flanges only when dimensions are within standard flange maximum metat conditions. How to specify To specify seattess valves for nominal pressures to 600 psi, use figure number shown. Describe as tong stroke, batanced stiding...

YARWAY BLOW-OFF VALVES SEATLESS, HARDSEAT AND UNIT TANDEM SEATLESS VALVES FOR PRESSURES TO 935 PSI - CLASS 250 TO 600 DIMENSIONS AND WEIGHTS Press. rating class Figure number Angle Straight- way

YARWAY BLOW-OFF VALVES SEATLESS, HARDSEAT AND UNIT TANDEM HARDSEAT VALVES FOR PRESSURES TO 2455 PSI - CLASS 600 AND 1500 The hardseat valve has a seat and disc design with flow entering under the seat. It is opened and closed by means of a handwheel and threaded rising stem. The stuffing box bushing and threaded yoke bushing provide a simple, sturdy guide for the stem. This valve has been designed with thick Stellite facings on the disc and seat to provide the hard wearing, anti-galling surfaces characteristic of Stellite. Operation Hardseat valves are available in angle or straightway styles,...

YARWAY BLOW-OFF VALVES SEATLESS, HARDSEAT AND UNIT TANDEM HARDSEAT VALVES FOR PRESSURES TO 2455 PSI - CLASS 600 AND 1500 Part Body Material Steel Nozzle with integral Seat Gland Split gland bushing Disc Disc nut Stuffing box bushing Yoke bushing Stem Handwheel Hex nut Hex nut Bolt Disc insert Packing Sleeve insert[3] Steel with integral Stellited face Steel Naval brass[2] Steel with stellited seating face Stainless steel Nickel alloy Naval brass Stainless steel Cast iron Steel Steel Steel Stainless steel (heat treated) Flexible graphite Steel ASME SA-216 WCB ASME SA-216 WCB[2] ASME SA-182 Grade...

YARWAY BLOW-OFF VALVES SEATLESS, HARDSEAT AND UNIT TANDEM HARDSEAT VALVES FOR PRESSURES TO 2455 PSI - CLASS 600 AND 1500

YARWAY BLOW-OFF VALVES SEATLESS, HARDSEAT AND UNIT TANDEM UNIT TANDEM VALVES FOR PRESSURES TO 3206 PSI - CLASS 300 TO 2500 The Yarway unit tandem valve features a one-piece steel block which serves as a common body for both blowing and sealing valves. This construction eliminates interconnecting welds, or bolts and gaskets where flanged valves are required, and makes the unit tandem a compact design. For valves with basic pressure rating to 600 psi (medium pressure unit tandem), the inlet valve is a hardseat type and the discharge valve is of the seatless type. For basic pressure ratings above...

1. 600 psi and lower rated valve; ASME SA-216 Gr. WCB 2. 600 psi and lower rated valve; Naval Brass. 3. 600 psi and lower rated valve; ASME SA-193 B7. Press. Blow-off Size NOTES: 1. Hardseat-seatless 2. Hardseat-hardseat

YARWAY BLOW-OFF VALVES SEATLESS, HARDSEAT AND UNIT TANDEM HARDSEAT-SEATLESS UNIT TANDEM VALVES Lubrication fitting Lubrication fitting Hardseat valve E NOTE 1. See page 3 “diameter of raised face” (in flange dimensions table) for “R” dimensions.