Yarway Hy-Drop 5800 Series Throttling Valve Types 5817 and 5827

Overview

The Yarway Hy-Drop 5800 Series throttling valve from Emerson is an angle-pattern, integral-bonnet valve built for severe high pressure drop service. It is designed first for continuous boiler blowdown, and Emerson also lists sampling, high-pressure vents, boiler feed pump bypass relief and other erosive, wiredrawing duties where flow velocity can destroy conventional globe or even venturi valves. Two configurations are offered: Type 5817 rated ASME B16.34 Class 1700 and Type 5827 rated Class 2700, both in NPS 1 and 1½ (DN 25 and 40) with socketweld ends.

Seven Star LLC supplies the Yarway Hy-Drop 5800 valve and its spare stem-disc assemblies to power plants, desalination plants, refineries and industrial boiler operators in Oman and the GCC. From Muscat we provide engineering support, from orifice selection and material choice to actuator options and replacement parts for existing installations.

Working Principle

Throttling valves in high-pressure water service usually fail through erosion, cavitation and wiredrawing. The Yarway Hy-Drop 5800 controls these forces through the shape of its flow path. Water passes through the annulus between a disc and a cylindrical seat and accelerates smoothly until it reaches the blunt end of the disc. There the flow area increases abruptly at the centre, and the pressure drop at the core makes the fluid flash toward the centre of the stream, inside a layer of unvaporized liquid that continues along and protects the sleeve wall. Emerson describes the resulting vaporization as so efficient that deterioration of the trim is virtually eliminated.

The valve also offers dual-range throttling. Turns 3 through 6 of the T-handle give throttling in the primary range, and from the sixth to the eighth turn the disc lifts beyond the primary control zone into a super-capacity blast range used to purge foreign particles from the line or to drain the system quickly during start-up and shutdown. Emerson does not recommend operation below three turns.

Engineering Design of the Yarway Hy-Drop 5800

A micrometer dial on the yoke allows accurate, repeatable settings and positive resetting after a blast. The quick-change stem-disc can be swapped in the same body to move to another orifice size, so a plant can adjust blowdown capacity without cutting the valve out. The disc is guided to prevent vibration and chatter, it is a loose design that seats in multiple positions to keep disc and seat aligned, and it has separate surfaces for shut-off and throttling. The disc is solid Stellite No. 21 and the seat is Stellite No. 6, resisting corrosion, galling and wiredrawing.

The body is ASME SA-182 grade F22 or ASME SA-105, the yoke is F22 and the packing is Garlock 98 with graphite lock rings in an extra-deep stuffing box. Both sizes have a listed weight of 25 lb (11.3 kg). If the seat wears, a Yarway reseating tool can cut a new seat in line, without removing the valve from the piping. For automation, the Yarway Hy-Drop 5800 can be supplied with Bettis™ XTE3000 electric actuators, Fisher™ Type 657 or 667 pneumatic actuators, or a mounting plate, and conversion kits allow manual valves to be motorized later.

In general terms, continuous blowdown is set once to hold boiler water chemistry within limits and then adjusted only when load or feedwater quality changes. That is why the repeatable micrometer setting matters: operators can record the dial position for each operating mode and return to it after a blast or maintenance. The Emerson datasheet provides valve selector curves for flashing water service and Cv formulas for steam, liquid and gas, so the orifice of the Yarway Hy-Drop 5800 can be chosen from boiler pressure and the required blowdown rate.

Key Features

The Yarway Hy-Drop 5800 offers the following:

• Dual-range throttling with a primary range plus a super-capacity blast range.
• Rapid energy dissipation that controls the destructive forces of high pressure drop service.
• A micrometer dial for accurate and repeatable settings with positive resetting.
• A quick-change stem-disc that converts the valve from one orifice size to another.
• A guided, loose disc with separate shut-off and throttling surfaces.
• Solid Stellite disc and Stellite seat to resist corrosion and wiredrawing.
• In-line reseating with the Yarway reseating tool.
• Manual T-handle, electric or pneumatic actuation for local, remote or automatic control.

Industrial Applications

The main duty of the Yarway Hy-Drop 5800 is continuous blowdown of drum boilers and heat recovery steam generators, where a small, steady flow of concentrated boiler water must be removed to control dissolved solids. It is equally suited to sample lines, high-pressure vents, drains and boiler feed pump bypass relief. In combined cycle power stations, independent water and power plants and refinery utilities in Oman, from Barka and Sohar to Salalah, these are classic locations where conventional globe valves suffer from wire-drawn seats and frequent replacement.

Seven Star LLC supplies the Yarway Hy-Drop 5800 together with blow-off valves, steam traps and desuperheaters for boiler houses. Related Emerson products on this site include the Yarway AT-18/28, AT-38/48 and TempLow 4300 desuperheater and the Yarway Series 751/761 repairable drip and tracer steam trap, while for severe anti-cavitation control valve duties the Masoneilan 41005 VRT high pressure anti-cavitation globe valve is also available.

Technical Specifications

The data below for the Yarway Hy-Drop 5800 comes from the Emerson datasheet VCTDS-00405-EN:

How to Order

For a quotation on the Yarway Hy-Drop 5800, send Seven Star LLC the boiler pressure, required blowdown rate, size, class, body material, orifice size and actuation. The Yarway Hy-Drop 5800 datasheet is available for download on this page. Our Muscat team will confirm availability and lead time and support selection, replacement and commissioning across Oman and the GCC.