Gas Blanketing with Broady Flow Control

Reducing Valves 2002

Series CL

Low PressureReducing Valves

Broady Flow Control

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The CompanyBroady Flow Control is an Independent Valve

Manufacturer, specialising in Innovative and effective

Solutions to satisfy it’s increasing customer

demands, challenges and problems in flow control.

Four key divisions

Relief. Safety relief. Pressure reducing &

sustaining valves.1

Overhaul & Refurbishment of Broady valves and other

selected valve manufacturer’s products and equipment.

4Pattern makers & Master founders of corrosion

resistant copper based alloys.

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Valves for Naval, Marine and other specialist applications.2

MARKET SECTORS

Naval & Marine

Chemical & Petrochemical

Food & Beverages

Industrial gases

Biotechnology

Mining

Fire protection

Oil & Gas

Pharmaceutical

Power generation

Protecting valuable products from atmospheric conditions orprotecting the atmosphere from hazardous vapors the CL gasblanketing regulator meets all your stringent demands. Over the past few years we have listened to our customer’s needsand requirements, developing a new valve that controls

Introduction

The CL - Reducing valves.

● Balanced inlet design giving little or no variation in reduced pressure when the

inlet pressure is variable.

● Spring loaded to give zero reduced pressure when the main spring is relaxed.

● Standard construction in Stainless Steel.

● Floating disc design giving repeatable shut off on “no flow” conditions.

● Very low pressure reduction, 10.0 mBar.

● Available with integral pressure gauge.

● Large orifice area to give good flow characteristics.

● Tapered plug giving excellent stability at full and low flows.

CL FEATURES

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pressure accurately from as little as 10.0 mBar. Broady Flow Control have been supplying the gas blanketing valvefor many years, obtaining many prestigious contracts throughout theworld. The valve is available in Stainless Steel as standard, flanged toeither PN or ANSI standards on short delivery schedules.

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Type CL Gas Blanketing Regulator; operation, installation

This shows a liquid in a pressure vessel under staticconditions. The CL is providing a positive atmosphere ofNitrogen on top of the liquid. Under static conditions thevalve is closed fully (known as a dead end condition)and will prevent more Nitrogen from enteringthe vessel.

This shows the liquid being pumped away. As the volume ofliquid in the tank drops the valve opens to allow nitrogenin thus maintaining a positive pressure. If the valve hasbeen sized correctly from liquid draw off rates the valvewill maintain pressure without the Nitrogen blanketpressure dropping significantly.

Once pumping ceasesthe valve re-closes.It is important to fitvacuum relief valves tothe vessel. When liquidenters the vessel thegas volume reducesand thus the blanketpressure rises. Withthe reducing valveclosed gas must beexpelled from thevessel via a vacuumrelief valve(can be supplied byBroady) to prevent anoverpressurecondition.

The main application for this valve is to provide a protective atmosphere within liquid storage vessels. It is used toeither protect the outside atmosphere from the liquid vapour, to stop liquids vaporising or to protect the liquid fromthe outside atmosphere. The valve can be used on any gases or liquids where there is a requirement for a low reduced pressure between10 mBar and 300 mBar.

FUNCTION OF THE VALVE WITHIN A STORAGE TANK

APPLICATIONS

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Parts key list

1 adjusting screw

2 valve body

3 cap

4 diaphragm

5 diaphragm

6 dome

7 bolt

8 locknut

9 locknut

10 nut

11 nut

12 pin

13 piston bolt

14 joint, top cap

15 valve lid assembly

16 quad ring

17 piston

18 saddle cap

19 saddle

20 valve seat

21 split collet

22 spring carrier

23 loading spring

24 spring

25 bush

and application.

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For best results it is recommendedthat the valve is fitted into ahorizontal pipe, with the adjustingscrew pointing down.

The CL is classified as a selfacting pressure regulator. As such theopening force is provided by a springunder compression.

Pressure is controlled downstreamby varying the orifice area within thevalve to give different flows, i.e. chokingthe flow through the valve nozzle via thevalve disc, which is directly connectedto the diaphragm, piston and spring.

The amount of flow through thereducing valve for an ideal gas isgoverned by the pressure drop across

the valve (P1 - P2), the flowing orificearea and the demand downstream ofthe valve. Reducing pressure acts onthe diaphragm and piston giving apressure force which acts against thespring. As reduced pressure rises thepressure force increases against thespring and thus the disc closes againstthe nozzle, consequently reducing theamount of flow through the valveallowing pressure to fall away.

As the pressure drops due to anincrease in demand downstream,the spring force becomes dominant,again forcing the valve open, givinga greater flow through the valve andthus allowing pressure to rise.

624

12

3

14

18

2

11

7

1

23

16

20

4/5

1710813

22

➤

➤ A

25

15

9

19

size

15NB

20NB

25NB

40NB

50NB

80NB

F to F with ANSI #150

A

241

241

238

300

338

442

OPERATION AND INSTALLATION

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1 A 100mm Type D Pressure reducing valve, flanged ANSI #150 FF,manufactured in Aluminium Bronze, with Monel trim and Nitrile seals and disc forseawater service, would be - 100-D-245N

Numbering system code: To simplify the selection and specifying of ReducingValves, a numbering system is used in which the digits have a distinct significance.

2 A 20mm Type CL pressure reducing valve, flanged ANSI #150RF,manufactured in Stainless Steel, with Viton disc and diaphragm, would be20-CL-233V

EXAMPLES

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How to order

To enable Broady Flow Control to offer the

most suitable valve for your service

please provide the following information at

the enquiry stage:

1 Inlet Pressure

2 Reduced or controlling pressure

3 Medium, with any relevant data,

specific gravity or molecular

weight etc.

4 Flowrate

5 Temperature

6 PED/CE Category*

7 Material requirements

8 Certification requirements

e.g. BS EN 10204 3.1b

*The first Five are important in selecting the

right size, with these five Broady can select

the right valve with confidence.

Reducing valves are classified as pressure

accessories; all products are approved by

Lloyds and carry the CE mark when

applicable. You do not need to state the

category level as this is based on the

pressure in BARg and the valve size.

Please note that sometimes we will be

unable to CE mark valves when the duty

and valve size require Sound Engineering

Practice (SEP) only.

20 - CL - 233V

Valve size in millimetres

Model type

code

0

1

2

3

4

5

6

7

8

code

0

1

2

3

4

5

6

7

8

bodymaterial

GM

SG

CS

SS

AB

Monel

Duplex

Hastelloy

Special

code

0

1

2

3

4

5

6

7

8

trimmaterial

brass

CS

SS

AB

Monel

Duplex

Hastelloy

Special

code

N

V

E

P

O

M

Z

disc/diaphragm

Nitrile

Viton

EPDM

PTFE

Neoprene

Metal

Special

endconnections

BSP

NPT

#150

#300

#600

PN16

PN25

PN40

Special

TESTING

The latest CL was specifically

designed for the demanding gas

blanketing service, using our own

state of the art flow test rig.

We can, on request mimic your

particular application on the test rig

and confirm the pressure reduction at a

designated flow.

Reducing Valves - A, AB, C6, C3, C7,

C8, C9, D, B2, W1

Safety relief valves to API and ASME -Type 3500

Other Safety and Relief Valves - 2600

● Speciality casting from in-house foundry in non-ferrous metals ● Full repair facilities.● The Series 3500 Safety Relief valve has been combination flow tested with bursting discs from continental (CDC) Disc Corporation.

Valves from the Broady range.

Fire Fighting - Hydrant Reducing Valves

Sustaining Valves - Type A, Type D, Type 9 Pilot Operated Safety Valves - Flowsafe

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Broady Flow Control Limited

English Street

Kingston upon Hull

East Yorkshire

HU3 2DU

telephone: +44 (0) 1482 619600

facsimilie: +44 (0) 1482 619700

email: sales@broady.co.uk

website: www.broady.co.uk