Flow Indicators
    Series-12FLW4011 Dial 4” & one Reed switch.
Series-12FLW4012 Dial 4” & two Reed switch.
Series-12FLW4013 Dial 4” & one Reed switch.
Series-12FLW4014 Dial 4” & two Reed switch.
Series-12FLW4015 Dial 6” & one Reed switch.
Series-12FLW4016 Dial 6” & two Reed switch.
    Flow Indicators included in this catalogue are mainly designed as a safely device looking to the need of an electrical signal on failure of forced circulation of liquid in pipe line.
  They Perform Following Functions
    Indicate specified rate of Full Flow in specified direction in known size of pipe.
    Operate on or two reed switches when rate of flow drops near to 70% of specified full flow. These switches can be used to initiate precautionary system or safety devices.
    These Flow indicators can be used in pipe lines carrying oil & water. Consider the case of furnace transformer in which one Flow Indicator can be mounted on suitable member of oil circulating pipe and one on water circulating pipe of heat-exchanger. Therefore these indicators can be used where equipment is cooled by water or oil circulation such as transformers, chemical equipment , heavy duty bearings, compressors etc. where stopage of flow of cooling liquid must result in inditiating precautionary system or safety device. The pointer of respective Flow Indicator will indicate wether desired rate of flow is maintained or not and switch will operate if the flow drops near to 70% to initiate precautionary system.
    (See Schematic)
    A suspended vane is used as sensor. Its surface is kept at right angle to direction of flow. When liquid starts flowing through pipe,the vane gets deflected alongwith vane shaft. This deflection is used to indicate flow inside the pipe and to operate reedswitch as follows.
    A pair of permanent magnets is used as glandless coupling. The driving magnet is connected with vane, therefore it rotates with vane and remains in liquid. The follower magnet, separated by a non-magnetic wall, is kept outside in air and aquires position corresponding to driving magnet. The follower magnet carries a pointer and a cam. The pointer is set to read the specified rate of full flow and the cam is set to operate reed switch when flow drops near 70% A return spring is used which acts in the opposite direction of flow. Hence any steady position of pointer is the result of equilibrium of force due to impinging liquid on vane, spring tension and weight of vane.
    The pointer does not remain steady for unsteady flow. The size and shape of vane and tension on return spring is adjusted to suit specified full flow. The vane occupies very small area out of full cross section of pipe at NO-FLOW position. At full flow it becomes almost parallel to flow. Hence there is practically no head-loos across Flow Indicator.
    Sometimes it is not possible to set Flow indicator because the Rate of Full is very less. In such cases an area reduction of nozzle type can be introduced just upstream to the position of sensing vane. The reduction of bore due to nozzle increases velocity near the vane and Flow Indicator works smoothly. The T-Mounting with such nozzle must be procured with Flow Indicator from us and position of nozzle upstream to vane will have to be maintained.
    The spread of flow indicating portion of dial is only about 700. Hence it is not possible to print more markings. Usually PUMP ON- PUMP OFF or FULL FLOW- NO FLOW type of limit markings are printed. Intermediate markings such as ALARM, TRIP are also printed if required. Besides, specifications such as value of full flow, liquid, pipe size and direction of flow are also printed. The background of dial is yellow. Direction indicating arrow is in red colour and all other markings in colourful.
    One or two reed switches provided. Their contact position can be set to NO or NC at full flow .In case of singal switch, it is set to operate near 70% when flow is falling. In case of two switches, both are mounted on same plate. Hence both operate at same rate of flow. But in case of two switches, both are mounting on same plate. Hence both operate at same rate of flow. But in order to satisfy design requirements, one switch can be set to operate near 80% and the other near 70% or one near 70% and the operate at lower value operate at same rate of flow, some switching differential is observed due of reed switch with magnet we cane modify setting suitably it switching requirements are clearly specified.
    Leads from reed switch/switches are brought into a terminal box positioned at the bottom of indicator. A terminal strip is provided. Terminals are accessible for wiring after removing cover. A hole with conduit threads is provided for fixing cable gland to box. Terminals are marked. Wiring should be done as per respective wiring diagrams.
    To introduce these Flow indicators in a pipe line a 'T-Mounting' for range of size from 12 mm (0.5”) to 200 mm (10.0”) N.B. Pipes. But customer can always specify if his requirement is different than the table on page ?.
    Static Pressure : At 7 Kg/Cm2 for base.
    Flow : Indicator is mounted on pipe. Water is allowed to flow in specified direction. Rate of flow is checked when pointer reads full flow. For liquids other than water, proportional rate of flow of water is check.
    Switch : Switch operation is checked by reduction and increasing flow in pipe line.
    Contact Rating : Switches are tested in laboratory at 5A, 240 V AC.
    Dielectric strength : Live terminals are checked at 2KV with body.
    A test Certificate is provided with each instrument.
    Full Flow - Each indicator is set in water-flowing condition. Pipe position, direction of flow are maintained. By adjusting a valve in pipe line, the specified rate of full flow is established, then the pointer is set to read the full flow mark This method of setting gives very accurate results as it is based on equilibrium of vane at full flow. In case of liquids other than water, proportional rate of flow of water is maintained for setting.
    Switch - After setting of pointer at full flow, switches are set in the sequence ordered by customer, Flow is reduced to check operation of switch & increased to check automatic resetting. The rate of flow at which switching occures is approximate. The switch position is kept adjustable to compensate difference in pipe gradient at site.
  Design Features
    1) Switch contacts are not affected by dust, humidity or corrosive atmosphere. 2) Switches can be serviced without need of stopping flow. 3) Causes negligible head-loss. 4) Low maintenance cost. 5) Robust construction & trouble free service. 6) Does not get damaged due to excess flow or reverse flow.
    How to order
    In order to be able to offer suitable Flow-Indicator, we need following information :
    1) Liquid in pipe. 2) Specific Gravity of liquid. 3) Rate of flow in LPM. 4) Pipe size. 5) Pipe position. 6) Direction of flow (Specify only one direction). 7) Switch setting. 8) Dial Marking. 9) Working Temperature 10) Working Pressure. 11) T. Mounting Required or Not Required. 12) Quality against each specification.
    1) Flow indicators are not interchangeable for different liquids, pipe dia, direction of flow or rate of full flow. Hence they should be ordered separately. 2) The rate of full flow is not adjustable. 3) The switch operation point is not adjustable. 4) We continuously review specifications and where appropriate, introduce modifications. We, therefore, reserve the right to change specifications in this catalogue without prior notice.
Part list
No. Description

1-Cover for terminal box
2-Base with mounging holes
3-Vane shaft
5-Product label
6-Cable entry
8-Reed switch

Hardware for indicator
(Supplied at extra cost)
M 12 x 65 Bolts, Nuts -4 Nos.
Water & Suitable gasket Accessories
(Supplied at extra cost if agreed)
T-Mounting Weldable connection
Flanges hardware

Note : P=PCD, H=No. of hole
d=hole diya

Series D W T G P H d kg.
12FLW4011 127 60 15 20 165 6 12 1.1
12FLW4012 127 62 15 20 165 6 12 1.1
12FLW4013 127 62 19 20 127 4 12 1.45
12FLW4014 127 62 19 20 127 4 12 1.45
12FLW4015 233 51 13 17 210 8 12 2.65
12FLW4016 233 51 13 17 210 8 12 2.65
COD NO. Of T-Mounting Pipe
Tee Pipe
mm inch d. L. T. H. A. PCD. B. N.
12FLWT 001 12 0.50 80
285 12 120 95 95
12FLWT 002 19 0.75 80
285 12 120 100 100
12FLWT 003 25 1.00 80
285 12 120 114 114
12FLWT 004 37 1.50 75
285 12 120 133 133
12FLWT 005 38 1.50 80
285 12 120 133 133
12FLWT 006 50 2.00 80
285 15 120 165 165
12FLWT 007 50 2.00 75
285 15 120 152 152
12FLWT 008 65 2.50 80
285 15 120 165 165
12FLWT 009 65 2.50 75
285 15 120 165 165
12FLWT 010 75 3.00 75
285 15 120 184 184
12FLWT 011 80 3.00 80
285 15 120 184 184
12FLWT 012 100 4.00 80
300 19 145 216 216
12FLWT 013 100 4.00 75
300 19 145 216 216
12FLWT 014 125 5.00 100
300 19 145 254 254
12FLWT 015 125 5.00 100
300 19 145 254 254
12FLWT 016 150 6.00 100
300 19 165 279 279
12FLWT 017 200 8.00 100
300 19 185 336 336
12FLWT 018 250 10.0 100
350 19 205 406 406
12FLWT 101 150 6.00 150
350 19 165 279 279
12FLWT 102 200 8.00 150
350 19 185 336 336
12FLWT 103 250 10.0 150 350 19 205 406 406 18 12
NO. DS/FI - 01 - 89.
    FI: Flow Indicator
TM: T-Mounting
SN: Order Specifications
RFF: Rate of Full Flow
C: Clearance
: Diameter of pipe on which Flow Indicator to be fitted
Fig.: Relates to Figures in Drg. CS-FI-88-01-RI.
    We manufacture different models of FI as per Catalogues FI-COND-2 & FS-M. Our Indicators are 'made to order' type. After knowing SN as per 'How to Order' column in Cat., we communicate with Indenter if we find any problem in SN. Invariably a solution is offered and mutually acceptable SN is finalized. However, our communication relates only to problems in manufacturing of FI. We do not consider the total layout of pipe line. It is likely, therefore, that a FI working in ideal conditions on Test Pad may not work smoothly after installation because of problems in layout. This Data Sheet, supported with illustrative Drg. CS-FI-88-01-RI, is prepared to give advance information of such problems in planning stage. It can also be referred to analyse any problem after installation of FI.
  2.1 We can set and supply Fls suitable for anyone out of 4 directions
    (Direction given considering dial in front)
    Left to right (HL) .. Fig. IA
Right to left (HR) .. Fig. 18
Vertically up (VU) .. Fig. IC
Vertically down (VD) .. Fig. ID
    Out of these any direction can be maintained. However, Fls set for one direction can not be used for other direction. Hence care should be taken while specifying direction of flow.
  2.2 Care should be taken while laying out the pipe line so that we can supply the best suited FI to you. We have given our recommendations as far as laying of pipe line is concerned on page 2 of this data sheet in Fig.1A, 1B, 1C, 1D.
  3.1 Our Fls work smoothly on higher rate of flow. Hence position FI in a member where Max. flow is expected in pipe layout.
    Some hints & recommendation for user of Flow Indicators :
1. We are manufacturing Flow Indicators for 4 different direction of Flow as illustrated in Fig. 8A, 8B, 8C 8D. The indicators are not interchangeable. Hence great care may be taken while specifying direction of Flow. Out of the four directions any one can be selected as per layout of pipe. However our rating for different directions may be considered while deciding the direction of flow.
2. In a pipe layout position has to be selected for installation of Flow Indicator. We have illustrated few conditions in Fig. 9A, 9B, 9C 9D. Please keep clearance ‘C’ as per respective situation so that flow of liquid remains steady in member of pipe where Flow Indicator is installed.
In adequate clearance may cause fluctuation in flow therefore resulting in bouncing of pointer. This can also result in nuisance operation of switch.
3. In some cases rate of flow is not sufficient to operate spring loaded vane smoothly. In such cases an area reducing nozzle can be fitted inside the pipe to increase velocity near vane. Such nozzle is hidden in pipe & always positioned upstream to the position of vane. Fig. 10 illustrates such scheme. This cases little head loss across the nozzle but we are using this method as it is most practical & effective.
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