FAQ - Frequently Asked Questions


GENERAL FAQ

Date founded
Who owns Glenfield Valves Ltd
Who are AVK Holdings a/s
Who are Glenfield within the AVK organisation
Where do Glenfield Valves manufacture
What do Glenfield manufacture & supply
Which markets do we supply
Can I source Guest & Chrimes Valves from Glenfield
What Quality Standards do Glenfield apply
Do Glenfield have representation in other countries
Where is the local Sales Office
Reference lists
Availability of drawings


FREE DISCHARGE VALVES (SERIES 857) FAQ

What is the purpose of a Free Discharge Valve
Where is a Free Discharge Valve used
What is the range of flow for Free Discharge Valves
How does the Free Discharge Valve work
Free Discharge Valve is not effected by cavitation
Design features of the Free Discharge Valve
Full design features


SUBMERGED DISCHARGE VALVE (SERIES 856) FAQ

What is the purpose of a Submerged Discharge Valve
Where is a Submerged Discharge Valve used
How does the Submerged Discharge Valve work
What is the benefit of the ported body
What is the range of flow for Submerged Discharge Valve
Design features for Sump / Submerged Discharge Valve
Full design details


RECOIL CHECK VALVES (SERIES 641) FAQ

Purpose of a Recoil Check Valve compared to conventional Swing Check
Rapid flow change
Multi pump system
Operation in vertical direction
Recoil Valve in sewerage application
Non slam design
Maximum velocity
Full design details


METAL SEATED GATE VALVES (SERIES 54) FAQ

What is the purpose of a Metal Seated Wedge Gate Valve
Suitability for throttling application
Low head coefficient
Suitable for end of line application
When is a gearbox required
Shoes and channels feature
Full clear bore
Sewerage applications
Full design details
Operating speed
Alternative design


BUTTERFLY VALVE (SERIES 756) FAQ

What is the purpose of a Butterfly Valve
Sealing
Operating speed
Velocity Rate
Bi directional flow
Mechanically retained seal ring
Replacement of seal ring
Benefits of double offset design
Resilient seal
Transmission of torque
Full design details





DATE FOUNDED
1852


WHO OWNS GLENFIELD VALVES LTD
Glenfield Valves Ltd became a member of AVK in 2001.


WHO ARE AVK HOLDINGS A/S
AVK Group is one of the worlds leading global manufacturers of valves, fittings, pipe joints, fire hydrants, pipe tapping & pipe repair equipment plus various kinds of piping accessories, with HQ in Denmark.


WHO ARE GLENFIELD WITHIN THE AVK ORGANISATION
Glenfield is the specialist centre for the manufacture for control valves, recoil check valves and large gate valves.


WHERE DO GLENFIELD VALVES MANUFACTURE
Glenfield valves manufacture valves in Kilmarnock, Scotland, UK, see map.


WHAT DO GLENFIELD MANUFACTURE & SUPPLY
Metal seated gate valves; butterfly valves; recoil check valves; swing check valves; air valves; ball float valves; auto control valves; in line regulating valves; Free discharge valves; submerged discharge valves; underground hydrants, refer to data sheets.


WHICH MARKETS DO WE SUPPLY
Dams and reservoirs; transmission pipelne; waterworks.


CAN I SOURCE GUEST & CHRIMES VALVES FROM GLENFIELD
AVK purchased G&C in 2002 from Saint Gobain, we do not supply G&C however, Glenfield manufacture similar gate valves from this manufacturer.


WHAT QUALITY STANDARDS DO GLENFIELD APPLY
ISO 9001:2000, WRAS etc, please refer to quality section in the web site.


DO GLENFIELD HAVE REPRESENTATION IN OTHER COUNTRIES
Glenfield have sales support throughout the world, refer to contact list within this web site.


WHERE IS THE LOCAL SALES OFFICE
Glenfield sales is based in the Kilmarnock Factory refer to contact list for your local contacts.


REFERENCE LISTS
Reference lists are available on request.


AVAILABILITY OF DRAWINGS
Data sheets and cad block drawings are available on this Web Site.







WHAT IS THE PURPOSE OF A FREE DISCHARGE VALVE
This valve provides energy dissipation and flow control at the end / outlet from a pipework system.


WHERE IS A FREE DISCHARGE VALVE USED
Primarily they are used in bottom outlet arrangements from dams and reservoirs, where it may be necessary to bypass a turbine, provide compensation flow to a river or provide rapid drawdown of dam water level or to provide desilting.

The energy dissipation is effected by discharging a thin cylindrical curtain of water into the atmosphere where it disintegrates and loses most of its energy, this water then falls in droplets onto a suitably sized stilling pond.


WHAT IS THE RANGE OF FLOW FOR FREE DISCHARGE VALVES
The valve is designed for operation under high flow rates and nominal bore flow rates are based on 10 15 M/sec.


HOW DOES THE FREE DISCHARGE VALVE WORK
The flow enters the valve where it is split by means of the internal guide vanes and discharged over a fixed conical shaped outlet. The flow is induced by retracting the horizontal stainless steel sleeve, which permits the thin high velocity cylindrical jet to be discharged.


FREE DISCHARGE VALVE IS NOT EFFECTED BY CAVITATION
The energy break takes place in the atmosphere thus no cavitation is experienced. The sleeve being cylindrical operates in a state of hydraulic balance hence operational forces are minimised.


DESIGN FEATURES OF THE FREE DISCHARGE VALVE
The valve body barrel and cone is of one piece design and of robust cast construction, it is therefore less prone to vibration than welded types.
The valves are proven in dams all over the world.


FULL DESIGN FEATURES
Refer to data sheets within web site







WHAT IS THE PURPOSE OF A SUBMERGED DISCHARGE VALVE
The valves provide flow control and energy dissipation at the outlet of dams and reservoirs and in view of their design can be also be used for inlet control.


WHERE IS A SUBMERGED DISCHARGE VALVE USED
Primarily they are used in bottom outlet arrangements from Dams & Reservoirs similar to Free Discharge Valve, In operation they discharge into a collection sump from where the water can be conducted to river, treatment works or other storage facility.


HOW DOES THE SUBMERGED DISCHARGE VALVE WORK
Water is supplied horizontally via an upstream pipework system and enters the valve horizontally where the valve bend turns the flow through 90 degrees vertically downwards. At the bottom of the valve the flow is again turned through 90 degrees and is discharged horizontally and radially through specially shaped apertures into the ample sized stilling sump.
The energy being released underwater enables the discharge to be quiet with minimum vibration.


WHAT IS THE BENEFIT OF THE PORTED BODY
Near linear control.


WHAT IS THE RANGE OF FLOW FOR SUBMERGED DISCHARGE VALVE
The key parameters relating to this arrangement ie valve and sump include an inlet velocity maximum of 6 m/sec and a downpipe rate of not more than 12m/sec.


DESIGN FEATURES FOR SUMP / SUBMERGED DISCHARGE VALVE
Sump details and water depth are also important. The sump sides are based on S=1.8 x Q1/2 where Q is in cusecs. The minimum side length should be taken as 2.5m in view if the jet exit velocity.

The water depth calculation ensures cavitation free operation.

Although not always necessary it is good practice to line the sump sides with ss plate to the height of the valve openings.

Corner filets should be included in the sump design thus giving a smooth free surface.

The valve should be installed with its base at least 50mm above sump floor.


FULL DESIGN DETAILS
Refer to data sheets within web site.







PURPOSE OF A RECOIL CHECK VALVE COMPARED TO CONVENTIONAL SWING CHECK
Generally most systems duties are catered for by the use of conventional check valve designs or by the addition of lever and weight. However in systems of rapid reflux and high deceleration, the rapid acting, high performance Glenfield recoil is required.


RAPID FLOW CHANGE
Recoil self acting valve should be specified.


MULTI PUMP SYSTEM
Recoil self acting valves are more capable of handling extremely rapid flow reversal and reflux conditions the swing check valve can not handle this type of duty.


OPERATION IN VERTICAL DIRECTION
Not suitable, valve is designed for use in horizontal position.


RECOIL VALVE IN SEWERAGE APPLICATION
Yes, if sewerage is finely comminuted.


NON SLAM DESIGN
Optimum non slam performance is obtained under all operating conditions of severe reflux.


MAXIMUM VELOCITY
3m/sec for severe conditions up to maximum 5m/sec. Refer to Glenfield for guidance.


FULL DESIGN DETAILS
Refer to data sheets within web site.







WHAT IS THE PURPOSE OF A METAL SEATED WEDGE GATE VALVE
To isolate or sectionalise any piece of equipment or length of pipeline in water or sewerage system.


SUITABILITY FOR THROTTLING APPLICATION
No not recommended, the valves have a low head loss coefficient thus closing these valves results in no effect until almost closed then possibility of turbulant flow throug small gap can result in cavitation.


LOW HEAD COEFFICIENT
Ideal for low pressure drop and pump efficiency as gate is outside flow path.


SUITABLE FOR END OF LINE APPLICATION
Yes on application as this is a onerous application, especially if the valve is the last valve in line and not restrained by two flanges. Review and special testing may be required.


WHEN IS A GEARBOX REQUIRED
As a general rule all valves of 700mm and greater must be fitted with a gearbox however calculation is required for smaller valves when high differential pressure is applied to the valve. The effort to open a valve manually can be calculated as 150nm roughly equivalent to effort applied by one man.


SHOES AND CHANNELS FEATURE
Can be fitted to 350mm and greater This feature provides accurate alignment and reduce friction and ensure corrosion free contact surfaces, these are particularly beneficial in applictions where valves operate in frequent mode of operation or when the valve is mounted at an angle or in horizontal configuration.


FULL CLEAR BORE
Low headloss, swabbing capability.


SEWERAGE APPLICATIONS
Ideal due to through bore design and no restrictions.


FULL DESIGN DETAILS
Refer to data sheets within web site.


OPERATING SPEED
300mm per minute / standard.


ALTERNATIVE DESIGN
Parallel face gate valves are available in certain sizes on application. Used where high velocities are envisaged or if non wedge design is specified.







WHAT IS THE PURPOSE OF A BUTTERFLY VALVE
Similar to gate valve and would be used in similar applications except sewerage where it is unsuitable.


SEALING
Resilient sealed on disc hense gives droptight closure.


OPERATING SPEED
600mm per minute / standard.


VELOCITY RATE
Velocity 5 m/sec higher velocity is available by special review.


BI DIRECTIONAL FLOW
Yes, if advised at order award.


MECHANICALLY RETAINED SEAL RING
Seat ring in body, integral, bronze and stainless steel available.


REPLACEMENT OF SEAL RING
Possible in situ.


BENEFITS OF DOUBLE OFFSET DESIGN
Minimum seal wear.


RESILIENT SEAL
Droptight shutoff.


TRANSMISSION OF TORQUE
Gearbox fitted as standard, actuator can be supplied if required.


FULL DESIGN DETAILS
Refer to data sheets within web site.



 


























































































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Glenfield Valves Limited

Telephone+44 (0) 1563 521150

Email

BSI

SABS

WRAS

AWWA

British Water

 

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