IntroductionSolartron Mobrey originally enteredthe industrial boiler control marketin 1923 with a range of steamoperated equipment. Since thattime the range has expanded tocover most aspects of controlassociated with the boiler house.Products range from electro-mechanical level devices tosophisticated electronic energysaving products that form a majorstep towards the fully automatedboilerhouse. These reliableproducts are described in greaterdetail on the following pages andeach carries the quality and serviceguarantee synonymous with theSolartron Mobrey name.

1234process measurement solutions

Data sheetBP100

MobreyBoiler water level controls

Alarm and Pump ControlMobrey Vertical Air Break Controlsare a comprehensive range ofmagnetically operated water levelcontrols. They are designed tomeet all the requirements forautomatic on/off control of boilerfeed pump, burner cut-out, highand/or low level alarm or anycombination of these. They complyfully with the recommendation ofThe British Health and SafetyExecutive Guidance Note P.M.5,and SAFed PSG2.

Float operated controls also complywith European standards TRD604.BS pr EN12953-9 and 12952-11when used in conjuction with theACCS unit described in BP203.

Fail Safety, High Integrity, SelfMonitoringFloat operated level controls areinherently Fail-Safe and complyfully with the definitions for thisparameter as stated by UK andEuropean Standards.

Float controls can be made tocomply with the definitions of HighIntegrity and Self Monitoring by theaddition of automatic checkingequipment as described inSolartron Mobrey leaflet BP203.The equipment is unique becauseit actually carries out a dynamictest on the level equipment, whichis a more searching requirementthan an electrical integrity test.Again this equipment fully complieswith the requirements of PM5,TRD604, SAFed PSG2 theharmonised European StandardsBS pr EN12953-9 and 12592-11.

Conversion HeadsThese VABC heads are designed tofit into existing float chambers, andprovide an economical method ofupdating boiler water level controlsto the latest models. Conversionheads are available for on/offcontrols and modulators.

Modulating water level controllersThe Solartron Mobrey Controller isa single element electro-hydrauliccontrol with an electronicfeedback. The system comprises acontrol unit float chamber, afeedline modulating valve and acontrol box. It is used for thethrottle control with the modulatingvalve in the feedline.

• Fully in accordance with the requirements of P.M.5, TRD604. BS prEN12953-9 and 12952-11 and SAFed PSG2.

Sequencing blowdown valvesThe Solartron Mobrey SequencingValve is designed to function as amanually operated combined waterisolating valve and sequencingvalve. It provides positive purgingof the water connection, floatchamber and steam connection ofa boiler control as required by

P.M.5, TRD604. BS prEN12953-9 and 12952-11 and SAFed PSG2.

Vertical air break alarm and pump controlsOperating LevelsDifferentialsEach switch has a nominal fixedwater level differential of 25mmbetween circuits A-A and B-B.To obtain a differential greater than25mm, two switch units must beused.The minimum water level differentialfor two switch units is 33mm, withswitch centres positioned 8mmapart.

Electrical CharacteristicsSingle-pole double-throw operationfor :ACMaximum voltage 440VMaximum Current 5AMinimum Power Factor 0.4Maximum Power 2000VADCResistiveMaximum Power 100WMaximum Voltage 250VMaximum Current 5AInductiveMaximum Voltage 250V*Maximum Current 0.5AMaximum Time Constant 40 msMaximum Power 100W*Maximum up to 2A dependentupon time constant of ciruit, consultfactory

Switches must not be used for thedirect starting of motors. Contactsshould be wired in series with theoperating coils of relays, contactstarters or solenoid valves, and fusedseparately.Two 25mm BS.4568 cable entriesare provided for the electricalconnections. A sufficient length offlexible cable must be fitted topermit easy removal of the switchhead and float assembly for routinemaintenance.

62mm range 37mm adjustment + 25mm fixed differential = 62mm150mm range 125mm adjustment + 25mm fixed differential = 150mm250mm range 225mm adjustment + 25mm fixed differential = 250mm

2 x SPSTAA make on riseBB make on fall

Link for SPDT/SPCO

The maximum adjustable differentialfor two switch machines will varywith the operating range of eachmodel, i.e. the distance betweenrising and falling level which isrequired to operate the switchespositioned at the extreme ends oftheir adjustments - Fig. 2.Switch adjustment - Fig. 1 and 2.Switches have adjustments asfollows:

DescriptionThe Solartron Mobrey Vertical AirBreak Controls (VABC) are acomphrensive range of magneticallyoperated water level controls forsteam boilers. They are designed tomeet all requirements for automaticon/off control of boiler feed pump,burner cut out, high and/or low levelalarm or any combination of thesecomplying fully with therecommendations of the BritishHealth and Safety Executive, PM5and SAFed PSG2 as well asEuropean Standards TRD604, andBS pr EN12952-11 and 1253-9when used in conjunction with theACCS unit. See BP203. Refer toFig. 6 for typical installations.Models available with Industrial(NEMA4), or Marine Heads.TUV approved models are availablein Chambers and for DirectMounting on application.

OperationThe Solartron Mobrey VABC is ofglandless constuction. A primarypermanent magnet attached to thefloat rod slides vertically inside a non-magnetic stainless steel centre tubeand transmits the movements of thefloat to a secondary magnet in eachswitch unit. There are two pairs ofcontacts which are operated with asnap action and held by repulsionbetween the secondary magnet andthe tertiary magnet of the switch unitassembly.

Fig. 162mm Single switch

Fig. 2150 or 250mm Range two switch

Additionalswitches may beadded asoptional extras

Maximumswitchingrange62mm

Lower stop

Upper stop

Maximumswitchingrange150mm or250mm

A B

A B

Dimensions and ordering information : Chamber mounted models

Explanation of type numbersThe type numbers are arbitraryexcept that BX denotes chambermounting and BD direct mounting.The stroke number indicates thenumber of switch units fitted asstandard. When extra switches arerequired this stroke number willindicate the total number ofswitches to be provided.

If the models shown here do notmeet your specific requirements,please contact Solartron Mobrey forassistance.

When Marine models are requiredthe letter ‘M’ should be insertedafter the letters BX and before thenumber, e.g., the Industrial andNEMA 4 Model BX05/2 becomesBXM05/2 when in Marineconstruction.Marine type approvals:American Bureau of ShippingBureau VeritasGermanischer LloydLloyds Register of ShippingDet Norske VeritasRussian Maritime Register ofShipping

Coverremovalheight

100

H1

W

G

L

H

Lowestoperatinglevel band

Fig. 3

Multi-switch 120, 150,215, 250mm ranges

100

H1

W

G

L

H

Lowestoperatinglevel band

Fig. 4

TypeNumber

OperatingRange

No. ofSwitchesStd. Max

Flanged & ScrewedConnections

Dimensions

BX02/1BX05/2BX07/2

BX09/1BX10/2BX11/2

BX12/1BX13/2BX14/2

62

150

250

62

150

250

62

150

250

1

2

2

1

2

2

1

2

2

-

4

6

-

4

6

-

4

6

BS4504.25-16/11

BS4504.25-16/11

BS4504.25-16/11

BS4504.25-40/2

BS4504.25-40/2

BS4504.25-40/2

BS4504.25-40/2

BS4504.25-40/2

BS4504.25-40/2

C

-

-

-

-

-

-

-

-

-

G

102

102

102

87

87

87

102

100

100

H

193

293

393

193

293

393

193

293

393

H1

303

497

602

303

497

602

303

497

602

L

366

468

557

366

468

557

559

559

559

W

182

277

370

182

277

370

372

372

372

F

160

160

160

160

160

160

160

160

160

Cast iron chamber - working pressure: 13kg/cm2

Fabricated steel chamber - working pressure: 21kg/cm2

Fabricated steel chamber - working pressure: 32kg/cm2

TUV approved models (side andside connections only) are availableon request. Before ordering pleaserefer to Solartron Mobrey.

C

100

TypeNumber

OperatingRange

No. ofSwitchesStd. Max

FlangedConnections

Dimensions

62

62

62

120

120

150

250

62

62

120

150

150

215

215

62

150

250

1

1

1

2

2

2

2

1

1

2

2

2

2

2

1

2

2

-

-

-

4

4

4

6

-

-

4

4

4

6

6

-

4

6

25-16/11

20-16/11

20-16/11

20-16/11

20-16/11

25-16/11

25-16/11

20-40/2

25-40/2

20-40/2

20-40/2

25-40/2

20-40/2

25-40/2

25-40/2

25-40/2

25-40/2

C

216

180

180

180

180

216

317

270

270

270

270

270

270

270

350

350

350

G

102

100

135

100

135

102

102

100

100

100

100

100

100

100

112

112

112

H

193

193

193

293

293

293

393

193

193

293

293

393

393

393

193

293

393

H1

303

303

303

497

497

497

597

303

303

497

497

497

602

602

303

497

597

L

448

480

480

480

480

448

557

570

570

570

570

570

570

570

595

595

595

W

277

240

240

240

240

277

370

335

335

335

335

335

335

335

372

372

372

F

160

160

160

160

160

160

160

160

160

160

160

160

160

160

160

160

160

ScrewedBottomConn.BSP

1”

1”

1”

1”

1”

1”

1”

½”

½”

½”

½”

½”

½”

½”

½”

½”

½”

Fabricated steel chamber - working pressure: 32kg/cm2

Fabricated steel chamber - working pressure: 21kg/cm2

Cast iron chamber - working pressure: 13kg/cm2

BX03/1BX15/1BX87/1BX16/2BX88/2BX06/2BX08/2

BX17/1BX45/1BX18/2BX19/2BX20/2BX21/2BX22/2

BX23/1BX24/2BX25/2

Chamber Mounted Controls

Float Chambers - manufactured inapproved materials :-

Cast iron equal to BS. 1452 Grade17 for up to 13kg/cm2 rating.Fabricated steel BS.3602 - HFS 27for both 21kg/cm2 and 32kg/cm2ratings. For chamber dimensionsand process connectionsarrangement see dimension chartfigures 3 and 4.

Switch head - containing one ormore switch units mounted in ahousing comprising a die-cast basewith a zinc coated mild steel casing.Two 25mm BS.4568 cable entriesare provided.

Switch units - have single poledouble throw contacts, are latchingand are positioned and held in placeby clamp screws.

Centre tube - made of non-magneticstainless steel and expanded intothe top cover flange, it is fitted witha stop cap which also acts as aguide for the float rod carrying theprimary magnet.

Float - manufactured in monelmetal.

Float rod - manufactured in stainlesssteel.

For details on self testing/monitoring of chamber mounted controls refer toleaflet BP203.

The Chamber band mark indicates the lowest adjustment position of low level alarm and it is our recommendationthat the positioning of the boiler control chambers relative to the water level gauge glasses and the N.W.L. is suchthat there is always water visible in the gauge glass even at the lowest operating band level.

Typical mounting arrangementsArrangements of Mobrey Vertical Air Break Controls on various types of boilerFig. 6

Side and bottom entrychamber with sequencingvalve on horizontal boiler

Side and bottom entrychamber with sequencingvalve on vertical boiler

Side and side entrychamber onhorizontal boiler

Side and side entrychamber on steam drumof water tube boiler

Fig. 5

Switchhead

Centre tube

Magnet

Stop cap

Side connection

Switch units

Chamber

Float rod

Lowest operatinglevel band

Float

Bottomconnection

NWL NWL NWL

NWL

Conversion Heads

Ordering InformationType Numbers

• Save - Time - Money - Inconvenience

• Conforms fully to PM5 requirements.

• Uses existing wiring andchambers

If you cannot see the model numberof your existing control listed here,or are unsure of which new model toorder, please do not hesitate tocontact Solartron Mobrey for furtherinformation.

Old unitnumbers

High and lowalarms100-MS6/F263102-MS6/F263129-MS70/F299129-MS71/F300133-MS70/F299133-MS71/F300125-MS71/F301

Pump control and1st low alarms220-MS12/F284220-MS16/F284 24-MS12/F216 24-MS16/F216 65-MS26/F22 64-MS26/F280125-MS72/F295125-MS76/F295

Single alarms 2ndlow125-MS73/F296214-S90/F50 14-S90/F50215-S90/F50 15-S90/F50 17-S101/F50 18-S90/F50

Modulatingcontrols3031030295

Replacementunit

C250/2C250/2F250/2F250/2F250/2F250/2F250/2

C150/2C150/2C150/2C150/2C150/2C150/2C150/2C150/2

Features

DescriptionThese Mobrey Vertical Air Breakcontrol heads are specificallydesigned to provide an economicmethod of updating old Mobreymercury switch controls to the latestmodels. These ‘Conversion Heads’will fit into existing chambers, andprovide on/off pump control andalarm function.

Conversion Heads are also availablefor updating old Mobrey TeleflexModulators.A suitably adapted version of theModulating Control head and floatunit is provided for fitting into theexisting float chamber. it will benecessary to replace the feed linevalve with its modern counterpart andto provide the modern electroniccontrol box.

NoteIn all cases the type number of theexisting equipment must be givenwhen ordering.This is to enable us to check themodel number and the float rodlength to be provided.For the modulating control the basicinformation for sizing the valve lidand seat will be required.

StandardVABC head

Flange tosuitchamber

Existingchamber

Standardfloat unit (rodlength to suitchamber)

Direct mounted water level controllersDirect mounted modelsStandard modelsDirect Mounted Vertical Air BreakControls employ the same principlesof operation and piece parts as thechamber mounted equivalents exceptthat the chamber is exchanged for alarge round flange and the tubeassembly for mounting the controldirectly on to the boiler shellconnection. A stilling or guide tubeshould be provided, which may befixed or removable, to ensure that thefloat rod is not damaged and thecorrect vertical movement is achieved.Direct mounted controlsincorporating test facilitiesThese controls have the provision fortesting the operation of themechanism without lowering the levelof water in the boiler. Testing can beinitiated manually or by a timer.U.K. Patent 1279504 or 1473939and foreign equivalents.Hydraulic cup test facilityThe test is achieved by lowering thefloat to the low water alarm level, bythe following means :

The float road includes a cup, abovethe float, which is fed with waterfrom the boiler feed pump via smallbore pipework and valves through thecontrol mounting flange (see fig. 7)for approximately 24 seconds. Theadditional weight overcomes thebuoyancy of the float, causing it tosink, stop the burner firing andoperate the alarm system. Afterclosing the test valve in the supplyfrom the feed pump to the control, asmall hole in the bottom of the cupdrains off the water, permitting thefloat to rise to the normal operatingposition. Control of the water supply tothe cup can alternatively be by meansof a solenoid valve, which can beinitiated by a timer or a manually

operated push button.In this design the alarm switchremains fully adjustable.Electromagnetic test facilityThe switch head includes aninductive coil below the single switchsubassembly (Fig. 8). This surroundsan armature located inside thestainless steel centre tube and fixedto the float rod.To initiate the test cycle, the coil canbe energised by a timer or a manuallyoperated push button and the floatwill be thrust downwards to stop theburner firing and operate the alarmsystem. When the coil is de-energised the float rises to its normallevel. In this design the alarm switchunit is not adjustable.

Type number

StandardBD01/1BD02/2BD03/2BD04/1BD05/2BD06/2

Working press.at saturatedsteam kg/cm2

21.0

32.0

Operatingrange

62

150

250

62

150

250

62

150

250

-

-

No ofswitches std.max. 1

2

2

1

2

2

1

2

2

1

1

1

4

6

1

4

6

1

4

6

-

-

Connection KBS4504

100-40/2

100-40/2

100-40/2

BM128mm sq

100-40/2

Float dimlength dia

152 x 67

155 x 90

155 x 90

155 x 90

DMin

77

100

100

100

DimensionsH

193

293

393

193

293

393

193

293

393

293

293

H1

303

497

597

303

497

597

303

497

597

497

497

Max. floatrod length

765

1016

1016

1016

Pressures up to 32kg/cm2 available on request

Dimensions and Ordering Informaton : Direct Mounted Models

Hydraulic cuptest facilityBDT01/1BDT02/2BDT03/2Electromagnetictest facilityBDT04/1BDT05/1

32.0

21.0

32.0

Switch units

Non-return valve

IsolatingvalveTest valve

Float rod

Float

Switch head

Centre tube

MagnetCover flangeStop cap

Hydraulic cup

Drain hole

Switch units

Solenoidarmature

Test valveFloat rod

Float

Stop cap

Stilling orguide tube

MagnetSolenoid coil

Fig. 7Hydraulic cup test facility model

Fig. 8Electromagnetic test facility model

H1

HK

D

162mm

Flangedstilling orguide tube

4 holesØ13

Lowest possibleoperating level

Boiler tubes 20

Single switch direct mounting -Standard models

H1H

K

D

162mm

Flangedstilling orguide tube

4 holesØ13

Lowestpossibleoperating level Boiler tubes

20

Multiple switch direct mounting -Standard models

H1

HK

D

162mm

Flangedstilling orguide tube 4 holes

Ø13

Lowestpossibleoperatinglevel

Boiler tubes20

Multiple switch direct mounting -with hydraulic cup test facility

H1

HK

D

162mm

Flangedstilling orguide tube 4 holes

Ø13

Lowestpossibleoperatinglevel

Boiler tubes20

Multiple switch direct mounting -with hydraulic cup test facility

H1HK

D

182mm

Flangedstilling orguide tube

4 holesØ13

Lowestpossibleoperatinglevel 30

Multiple switch direct mounting -with hydraulic cup test facility

For information on Self monitoring / Self testing Mobrey controls, please refer to leaflet BP203.

DescriptionThe Solartron Mobrey ModulatingController is a single element electro-hydraulic control with an electronicfeedback system comprising:i) A control unit float chamber,

mounted on the boiler shell,fitted with an Inductance Coil ‘A’head assembly which can bemade suitable for either Industrialor Marine Applications.

ii) A flanged modulating valve, fittedwith an Inductance Coil ‘B’ andtwin solenoid valve assembly,which is mounted in the boilerfeed water line.

iii)An electronic control box.

OperationA positive change of water level inthe boiler alters the inductancevalue of Coil “A” causing animbalance in the system. Thissignal is transmitted through theelectronic control box to theappropriate solenoid valve on themodulating valve thus producing achange of hydraulic pressure on thepiston assembly, the movement ofwhich modulates the flow of water tothe boiler.Simultaneously this same verticaltravel creates a change in theinductance value of Coil “B” untilthe balance is restored, thus closingthe solenoid valve and hydraulicallylocking the modulating valvespindle. This sequence is repeatedin very small steps until the feedwater input equals the requiredevaporation rate of the boiler.To prevent the modulating valve

responding to random watermovement against the generaldirection of level change, a 13mmreversal or (dead) band isincorporated in the electroniccircuitry.Low water alarm and burner cut outcontacts are also provided within thecontrol box to operate when the waterlevel falls to a predeterminedposition.

Installation Note:For the further safety of boilers it isrecommended that the MobreyControl Unit is mounted on a MobreySequencing Valve.The water connection from the boilerto the float chamber should be asshort as possible and the controlhead float chamber should bemounted close to the gauge glasses.The chamber band mark indicatesthe lowest adjustment position of thelow level alarm and it is ourrecommendation that the positioningof the boiler control chambers relativeto the water level gauges glasses andthe N.W.L. is such that there isalways water visible in the gauge glasseven at the lowest operating bandlevel. If required our technical staffwill advise on individual installations.

General NoteModels shown are for 21kg/cm²maximum working pressure. Detailsof modules for 32kg/cm² will beprovided on request.

Important NoticeElectronic control box must not besubjected to either vibration orexcessive temperature. It is thereforerecommended that they are NOTmounted directly on to the boilershell.

Features• Inherently stable• Easily adjusted for individual

operating requirements• Instant reversion to hand control

in emergency.

Application NotesThrottle Control –• Modulating valve in feed line.• Suitable for automatic cold start

conditions.• Used for all pumps capable of

operating against a closeddischarge.

With a rising water level in the boiler,the modulating valve closesprogressively to reduce the rate offeed into the boiler. The size of valvelid is determined by the actualcapacity of the boiler plus anallowance. See nomogram on page 9.

Power failure and high watershutdown – with a third solenoidvalve

Where one pump is feeding more thanone boiler it is imperative that a boilercannot be overfilled.Therefore a third solenoid valve canbe installed on the modulating valvewhich is operated by either a loss ofpower on the boiler control circuit orthe high water alarm. In either casethe valve will be closed and preventfurther water entering the boiler. Thethird solenoid valve can be retrofittedto existing valves.

Common feed pump arrangementMulti-boiler installations operating ona common feed system require specialsizing consideration and full detailsshould be provided so that a suitablevalve can be recommended.

Modulating water level controllers

Boiler

Feed checkvalve

Modulating valve

PumpFeed tank

Control UnitsStandard control heads and chambers

TypenumberMaterial

Max. press.kg/cm2

Connections

ABCDEFG

81006

Cast iron

13

Side &bottomBS450425-16/11 468 100 102 277 390 430 -

81008

Fabricatedsteel

21

Side &sideND 25NW 25570100100335390430270

81951

Forgedsteel flange

21

DirectmountedBS4504100/40/2----390430-

81007

Fabricatedsteel

21

Side &bottomBS450425-40/246810087277390430-

Models are available for up to 32kg/cm2 steam working. Details on request

Control Box Electrical characteristics

Type number 80436 80660Input supply 240V ac 110V ac

50/60Hz + 10% 50/60Hz + 10%

Input circuit protected by 1 amp HRC fuse.Alarm and control relays protected by 2 amp HRC fuses.Relay contacts voltage free rating:-Max. voltage 250V ac Max. current 2 ampFacility available to special order for separate supply tosolenoid valves with 2 amp HRC maximum protection.Output option: 0-10V available on request.

IMPORTANT NOTICEElectronic control box must not be subjected to eithervibration or excessive temperature. It is thereforerecommended that they are not mounted directly on tothe boiler shell.Modulating Valves

Valve body: Cast steelMax. feed line pressure: 40kg/cm2

Min. feed line pressure: 5.3kg/cm2

Max. feed line temp.: 120oCFlanged BS4504-40-40/1(DIN ND40 NW40)and BS10 table H

Type number

80310/*80311/*80653/*80486/*80310/80435/*80311/80435/*80653/80435/*

Flanged

Table HND40NW40NW40Table HND40NW40

No. ofsolenoid valves

2222333

Electricalsupply230V ac 50Hz230V ac 50Hz110V ac 50Hz230V ac 60Hz230V ac 50Hz230V ac 50Hz110V ac 50Hz

* Stroke letter to indicate valve lid size required:

A 200 B 150C 406 D 140E 425

Note The internal trim on the Modulating valve can bechanged without the need to replace the valveshould operating conditions change.

85

6 Holes Ø 20.0

235

254

235 152

42

4 HolesØ 7.1

Ambient temperature: 1O - 60OCConduit connection 6 holes suitable for PG16

E

A

B

C

D

A

B

C

D

E

½” BSP

81006 81007 81008

A

B

C

D

E

F F

A

G

C

D

E

F

B

Sizing of Valve LidsA range of valve lids and associatedseats are available and provide linearflow characteristics. a table of cvvalues for water (S.G.=1) is givenbelow for valve lids in the fully openposition.

Type of Lid Cv = kg/hr for 1 kg/cm²

A 1,690B 2,260C 3,030D 4,100E 5,480F 7,480G 9,840H 13,520I 18,480

Note: J Lid available on requestfor larger boilers.

Formulae for determining the Cvvalue and correct size of valve lid aregiven below. The pressure dropacross the valve should be 1.4 kg/cm² or greater – normally, the higherthe pressure drop the better thedegree of control. The lid size isthat with the nearest Cv value abovethe calculated value.

In the following example, anallowance of 0.4 kg/cm² has beenmade for all feed line losses. Inpractice, the allowance should bethat of the installation underconsideration and may well be inexcess of 0.4 kg/cm², particularlywhere the feed pump is remote fromthe boiler and/or where an anti-syphon valve adjacent to the boilerfeed check valve has been fitted.

Mobrey Modulating Level Controller valve size chart

Note: Conversion heads to convert old Mobrey Teleflex modulators to the latest models are available.

CV= QP

WhereQ = Actual Evaporation of Boiler plus15 per cent margin kg/hr.P = Pump Discharge Pressure kg/cm²when passing Q quantity of waterminus (Boiler Maximum WorkingPressure plus 0.4 kg/cm²).Example:Boiler evaporation (actual)

= 4,000 kg/hr.Boiler Working Pressure

= 6.6 kg/cm²Pump Discharge Pressure atQ quantity

= 11 kg/cm²Cv= 4,000 + 15%

11—(6.6 + 0.4)=2.300

Lid required: Type C.

Type

of v

alve

lid

Pre

ssur

e dr

op ∆

P K

g/cm

2

Required flow throughvalve Kg/hr

Max rated boileroutput Kg/hr

Sequencing Blowdown Valves

DescriptionA purpose built flanged isolatingangle and sequencing valve with ½”BSP screwed drain connection andback seating features, all valve trimsare in stainless steel. It fullycomplies with the recommendationsof Health and Safety Executiveguidance note PM5 - forautomatically controlled steam andhot water boilers.

FunctionThe Mobrey sequencing valve isdesigned to function as a combinedwater isolating valve and asequencing valve to provide positivepurging of the water connection,float chamber and steam connectionof a boiler control.Blowdown of float chamber andconnections is effected separatelyand in a pre-determined sequenceby the operation of the singlespecially designed handwheel.

Features• One valve to provide separate

blowdown of:- Control Chamber- Steam Connection- Water Connection

• Blowdown by predeterminedsequence

• Stainless steel trim• Back seating ensures packings are

not subjected to continuouspressure

• Available with Imperial or MetricflangesAvailable for pressures up to 32kgs/cm²

Sequence of operation

Normal working valve open

Mid travel position waterconnection purged

Chamber, steam and waterconnections purged

Fully closed position steam connectionand chamber purged

NWL

NWL

NWL

NWL

Fig. 1 Fig. 2

Fig. 3 Fig. 4

Dimensions and Ordering Information

TypeNumber

FlangeConnectionsBS4504

MaterialBody andStuffing Box

MaximumWorkingPressure Bar

Dimensions

A B C

Models availble

80938 25-16/11 Cast Iron 13* 83 54 219

80947 25-25/21 Gunmetal 21 83 54 219

80951 25-40/1 Cast Steel 32 83 54 219

81390 BS10 Table H Gunmetal 21 83 54 210

*For Lloyds applications maximum W.P. is 10.5 Bar

Important

The blowdown connection should be piped directly to an independent covered drain, or tundish with removable lid,capable of accepting the full discharge without danger of blow-back. The bore of blowdown pipe should not be lessthan 12mm and the length should be kept as short as possible. Sight glasses must not be fitted in the blowdownline.

Connection to water leg½” BSPBlow down connection to drain

Mid travel position

Blowdown Procedure Card:

Solartron Mobrey produce a useful blowdown procedure card, part number BP109, which is available on request.

Steam and water FlowFlow meters are available forsteam, water and fuel flowmeasurement using orifice andlow energy loss averaging pitottube technology. Non intrusivemeters are available for liquidflow.

1 2 34

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Solartron Mobrey Limited158 Edinburgh Avenue Slough Berks UK SL1 4UETel: 01753 756600 Fax: 01753 823589e-mail: sales@solartron.com www.solartronmobrey.com

Solartron Mobrey GmbH Deutschland tel: 0211/99 808-0Solartron Mobrey Ltd China tel: 021 6353 5652Solartron Mobrey sp z o o Polska tel: 022 871 7865Solartron Mobrey AB Sverige tel: 08-725 01 00Solartron Mobrey SA France tel: 01.30.17.40.80Solartron Mobrey SA-NV Belgium tel: 02/465 3879Solartron Mobrey USA tel: (281) 398 7890

BP100April 04

The right is reserved to amenddetails given in this publicationwithout notice

Electronic ProbesSolartron Mobrey manufactures afull range of conductive andcapacitive probe controls forapplication on steam boilers. Thisequipment fully complies with thelatest boiler specifications.

Automatic Control CheckSystemThis product has been designedto provide high integrity and self-monitoring to float operatedcontrols in compliance with thelatest boiler standards

Smoke DensitySelf-calibrating, ObscurationMeters available on request

TDS Control, Timed BottomBlowdown,Remote Alarm & Shut downpanels

General LevelSolartron Mobrey is a level, flow,pressure, density and viscositymeasurement instrumentcompany. If you have a problemwe will have the solution

For UK and Eire markets only – Full customer service provision

Solartron Mobrey is able to provide a full design, installation, commissioning and maintenance service for theirsite installed instrumentation through their service division, Bestobell Service. This organisation is able to providea full boiler house installation and maintenance service and provide turnkey installation solutions covering allcontrol and instrumentation functions. The following gives a typical list of operations carried out by engineers andtechnicians directly employed by the company and operating through 5 regional offices throughout the UK

Associated Boiler Products

◗ Total compliance withunmanned boiler regulations,Health and Safety guidancenote PM5, SAFed PSG2, andBS prEN12953-9 and BSprEN12952-11 for both existingMobrey float controls andelectronic probe installation

◗ Steam and water flow monitoring,heat and mass flow calculation

using Solartron Mobrey’s uniquerange of products.

◗ Tank and level monitoringsolutions using SolartronMobrey’s unique range ofproducts.

◗ Complete automation solutionsbringing together majormanufacturers equipment intoa single turnkey solution

Bestobell Service is anengineering company providingengineering solutions and is a fulloperating division of SolartronMobrey.

Insurance inspection High integrity, self-monitoring float controls

Electronic probeinstallation

Flowmetering

Head Office Scotland & N Ireland Northwest and Eire NortheastTel: 01753 756634 Tel : 0141 613 1441 Tel : 0161 483 0931 Tel : 01924 441960

756622 Fax: 0141 613 2093 Fax: 0161 483 4145 Fax: 01924 441850 756623

Fax: 01753 579523 Midlands SouthernTel : 0121 730 1900 Tel : 01474 355976Fax: 0121 730 3004 Fax: 01474 564349

a Roxboro Group Company