Yarway ARC Pump Protection Valves Series 9200, 9100 and 5300

Overview

The Yarway ARC pump protection valves, also called automatic recirculation control valves, are self-contained valves from Emerson that protect centrifugal pumps against overheating and damage at low flow. The range covers the Series 9200, Series 9100 and Series 5300 valves plus a matching back pressure regulator (BPR). According to Emerson, Yarway ARC valves have more than 40 years of service history, and they are offered in sizes from 1 to 14 in (DN 25 to 350), pressure ratings from ASME B16.34 Class 150 to Class 2500 and temperatures from -73 to 287 °C, in carbon steel, stainless steel, 6Mo, super duplex and NACE-compliant constructions.

Seven Star LLC supplies Yarway ARC valves to refineries, gas plants, power stations, desalination plants and pipeline operators in Oman and the GCC. From Muscat we provide engineering support, help collect the sizing data that Emerson requires, and coordinate documentation for project and maintenance orders.

Operating Principle

A centrifugal pump needs a minimum flow to stay stable and to carry away the heat generated by the impeller. When process demand falls, a Yarway ARC valve automatically opens a bypass to return part of the flow to the suction source, so that the pump never runs below its minimum. The heart of the Series 9200 and 9100 valves is a spring-loaded, flow-sensing check disc in the main line. The disc lifts in proportion to forward flow; as the forward flow drops, the disc moves toward its seat and, through the stem, opens characterized orifices in the bypass element. The valve therefore modulates recirculation to match the shortfall instead of recirculating continuously.

Because one body combines a flow sensing element, a main line check valve, a bypass control valve and a multistage pressure letdown device, the valve needs no instrument signal, no power source and no external control loop. In general, this removes the flow transmitter, control valve, orifice plates and wiring that a conventional minimum flow loop would require, which is why automatic recirculation valves are popular on boiler feed, product transfer and injection pumps.

Engineering Design of the Yarway ARC Range

The Yarway ARC Series 9200 is a modulating valve with a one-piece, bonnetless and packless body, a balanced bypass trim for two-stage pressure reduction and an internal vortex-inducing flow conditioner that reduces noise and cavitation. It is available from 2 to 14 in (DN 50 to 350) in ASME B16.34 Class 150 and 300, with raised face flanges to ASME B16.5. The Series 9100 shares the modulating principle in sizes from 1 to 8 in (DN 25 to 200) and Class 150, 300 and 600, with vibration guides and a snubber on the disc and all static seals so there is no leak path to atmosphere.

The Yarway ARC Series 5300 is intended for high-pressure feed pumps and is rated Class 900, 1500 and 2500 in sizes from 3 to 12 in (DN 80 to 300). It is an on/off design in which the main line check valve acts as the sensing element and pilots a recirculation valve with a cascade pressure-reducing element that turns the bypass flow through successive 90° changes of direction. Where the bypass line lacks back pressure, the Yarway BPR prevents flashing and cavitation downstream; it is offered in flanged sizes from 1½ to 6 in and wafer sizes from ¾ to 6 in, Class 150 to 1500.

Key Features

Engineers specify the Yarway ARC valves for these reasons:

• Precise, modulating recirculation control on Series 9200 and 9100 valves.
• An integral check valve that prevents reverse flow through the pump.
• Self-operating design with no electrical wiring, instrument air or control signals.
• Multistage pressure letdown that prevents cavitation in the valve and bypass piping.
• Only three pipe connections, which simplifies layout and pipe supports.
• Material options including WCB carbon steel, CF8M stainless steel, 6Mo, Zeron 100 super duplex and NACE MR0175 conformance.
• Flange options including DIN, BS, JIS, RTJ and FF faces in addition to ASME raised face.
• Flow loop testing with a performance curve supplied for valve orders, as described in the Emerson datasheet.

Industrial Applications

Yarway ARC valves are used on boiler feedwater pumps in power and desalination plants, on product and crude transfer pumps in refineries and terminals, on water injection and seawater lift pumps in upstream oil and gas, and on firewater and cooling water systems. The Series 9200 and 9100 suit the many low and medium pressure pumps found in petrochemical complexes in Sohar and Duqm, while the Series 5300 serves high-pressure boiler feed pumps in combined cycle and independent water and power plants in Oman and across the GCC.

Seven Star LLC supplies the Yarway ARC range with the full sizing workflow: we collect pump curves, minimum flow, fluid and temperature data on the Emerson ARC sizing data sheet and return a recommended model and size. Related Emerson steam 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, and for the pumps themselves see the KSB Multitec multistage high-pressure pump.

Technical Specifications

The following summary of the Yarway ARC range is taken from the Emerson datasheet VCTDS-00817-EN:

How to Order

To quote a Yarway ARC valve, send Seven Star LLC the pump duty point, minimum flow, fluid, temperature, pressure class and line sizes, or ask us for the sizing data sheet. The Yarway ARC datasheet can be downloaded from this page. Our team in Muscat will coordinate sizing, confirm availability and support delivery and commissioning throughout Oman and the GCC.