Installation & Operation Manual
Float Actuation Type
Tank Level Gauge
NIVOGAUGE MLF-1000
Manufactured by
Nivo Controls Pvt. Ltd.
104-115, Electronic Complex
Indore 452 010. INDIA
Contents
1
Application
1
2
Operating Principle
1
3
Installation
1
3.1
Installation on Fresh Tank
2
3.2
Installation on Existing Tank
5
4
Indicator Setting
6
4.1
Level Measurement
6
4.2
Adjustment of Indicator (Dial & Pointer Type)
6
4.3
Indicator Reading Procedure
7
4.4
Adjustment of Counter
7
4.5
Counter Reading Procedure
7
5
Operation
8
6
Checker Function
8
7
Cranking Function
8
8
Maintenance Guidelines
8
8.1
Periodic Maintenance
8
8.2
Troubleshooting
9
9
Spare Parts
96/MKT/49/V02
10
1
Application
The tank level gauge with float is used to measure and indicate tank liquid level in
oil refineries, oil depots, chemical and fertilizer plants, food industries etc.
2
Operating Principle
Figure 1 shows Tank Level Gauge operating principle. The Float (8) floats on the
surface of liquid due to its buoyancy.The level sensed is transmitted by means of a
Measuring Tape (1) and a Reduction Gear (3) to the Indicator (4). The Measuring
Tape Drum (5), is constantly kept, pre-tensioned by a Spring Motor (6). Thus there
is an equilibrium between the active force of float weight and spring tension. The
measuring system remains in steady state. When the level rises or falls, there is a
change in the active force of float weight, this force is immediately compensated by
the spring.The indication is adjusted linearly to the change in level.
Sheave Elbow (2)
Reduction Gear (3)
Indication (4)
1
2
3
4
Sprocket Wheel (7)
Measuring Tape Drum (5)
Measuring Tape (1)
Spring Motor (6)
Float
Guide Wire
Figure 1
3
Installation
Refer installation guidelines provided separately.
Correct installation of all mounting accessories on the tank is very important for
accurate indication of level.
Please Check and ensure that all accessories are mounted correctly as
shown in the installation diagram, as no alteration will be possible once
the tank is filled with liquid.
1
3.1 Installation on Fresh Tank A) GUIDE WIRE FIXING
In case of Cone Roof Tank
1.
2.
3.
Open top anchor cover mounted on
socket 1" BSP which is welded on top of
the tank. Pass the guide wire through
the center hole of the top anchor into the
tank and temporarily fix the upper end of
the guide wire to the top anchor by nut
(1) and (2) as shown in figure 2.
At the tank bottom, pass the wire
through the guide ring of the float and fix
it firmly to the bottom anchor with the
bolt and nut as shown in figure 3. Then
cut off excessive length and bend guide
wire end to prevent it from being caught
by the float.
At the top of the tank, fix the guide wire
as shown in figure 4. Pull guide wires
tensely and bend upper end of guide
wires through the slot in shaft. Clamp
upper end of the guide wire with nut (1)
and (2) and tighten the nut (3) to make
the spring sufficiently effective, i.e.
providing full tension to guide wire.
Then cut the guide wire off with about
100mm of surplus length.
1
Guide Wire
2
Figure 2
Figure 3
1
2
3
Figure 4
1. Take care not to fold or kink the guide wires.
2. Both the guide wires must be stretched vertically parallel each other.
3. Ensure proper fastening of guide wires with bottom anchor. It can
not be easily re-fastened in a filled tank.
In case of Floating Roof Tank and Gas Holder Tank, Guide Wire Fixing
is not required.
B) MEASURING TAPE SETTING
Prior to setting of Measuring Tape:
1. Remove Sheave Elbow Covers.
2. Remove Gauge Head Cover.
3. Insert Measuring Tape.
2
Measuring Tape
In case of Cone Roof Tank
1.
First pass one end of the measuring
tape into the tank through sheave elbow
located right above the tank. Pass the
other end (looped) into the gauge head
through sheave elbow located right
above the gauge head (figure 5).
Fix the looped end of measuring tape to
tape drum by locking screw (figure 6).
2.
3.
4.
Tank Roof
Pull the measuring tape inside the tank
up to the bottom and cut off leaving an
excessive length more than 1.5M as
measured from float connecting point
as shown in figure 7, then fasten the
tape to the float as shown in figure 8. For
tape fastening follow step 1, 2 and 3.
In the gauge head, turn the tape drum in
the direction indicated by arrow in figure
6 to tense the measuring tape.
Loop
Figure 5
Tape
Sprocket Wheel
The measuring tape may be severely
vibrated by surges and get disengaged
from sprocket pins, resulting in variation
of level reading. Tape guide is provided
to prevent such trouble. After tape
setting, set the tape guide at such a
position as it is located about 2 mm
away from the surface of sprocket wheel
as shown in figure 9.
Tape Drum
Locking Screw
Spring Drum
Figure 6
Tape
Tape
Tape
Shakle
65 mm
Tape Cut off Point
1.5 M
Float
Step 1
Step 2
Figure 7
Tape
Tape
Sprocket
Clip
Locking Screw
Tape Guide
(Maintain gap 2mm
approx. from sprocket)
Float
Step 3
Figure 9
Figure 8
3
Triangular Ring
In case of Floating Roof Tank
1.
Pass measuring tape end into gauge
head through sheave elbow located
right above the gauge head and pass
measuring wire end into the tank
through sheave elbow located right
above the tank as shown in figure 10.
Fix the looped end of measuring tape to
tape drum by locking screw (figure 6).
3.
Measuring Tape
Pull measuring wire inside the tank so
that the position of triangular ring
connecting wire and tape is left at about
150 mm below the sheave elbow
located above the gauge head (see
figure 11). Now cut the length of
measuring wire which is excess 1.5M
from tank bottom (see figure 8).
Figure 10
150mm
2.
Measuring Wire
Measuring Wire
Put the float between guide rods so that
it can move up and down freely as
shown in figure 12A.
Wind a stainless
steel wire f 0.6mm
about 10 to 15 turns
Fasten the measuring wire to the float
as shown in figure 12B.
Measuring Tape
4.
Repeat steps 3 & 4 of Cone Roof Tank.
Section 3.1B (figure 6 & 9).
Figure 11
Measuring Wire
Wind a stainless
steel wire f 0.6 mm
about 10 to 15 turns
Guide Rod
Float
A
B
Figure 12
In case of Gas Holder Tank
In case of Gas Holder Tank, fasten measuring wire directly to the hook welded on
tank top instead of the float.
Follow above sequence used for floating roof tank.
1. Take care not to bend, damage or kink measuring tape.
2. Ensure that tape is properly placed on the roller pulley.
3. Check connections between float and tape drum by slightly
rotating tape drum.
4
C) SPRING MOTOR SETTING
Spring Spool
1.
Tape Drum
2.
Remove both the locking screws of
spring drum (figure 13) and fix spring
end to spring drum with screw and nut.
Turn spring drum in direction indicated
by arrow in figure 14.
Spring Drum
Locking Screw
For fixing spring drum to tape drum, turn
tape drum counterclockwise duly until
tape is free from looseness.
3.
When tank is empty, fix spring motor to
tape drum by locking screw with two
turns left on the spring spool.
Figure 13
Screw & Nut
When the tank is filled with liquid,
measure liquid level and calculate
number of turns to be wound around the
spring drum by following equation:
Number of Turns
M1 2 M2
0.6
Figure 14
Where,
M1 = Measuring Span
M2 = Actual Liquid Level
Wind spring around spring drum by number
of turns as calculated above and fix it.
Correct
Wrong
Wrong
Spring Winding
1. Do not remove your hands from spring while winding spring on spring
drum. It will injure your hands if slipped.Wear hand gloves for safety.
2. While Spring Winding ensure that it is wound in correct direction
as shown above.
3.2 Installation on Existing
Tank
Guide Wire Fixing (Cone Roof Tank)
Guide Wire
When fluid is present in the tank and welding
is not possible, Anchor Weight is used with
the bottom anchor.
Float
Prior to commissioning, remove manhole
cover from tank and weld sockets onto it.
Open the Union Joint and Remove top
anchor covers from top anchors.
Bottom Anchor Weight
Guide Wire
1.
Fasten one end of guide wire to the
anchor weight with nut and bolt as
shown in figure 15 and pass the other
end through guide ring of float and fix
temporarily to top anchor.
Solid Wire
Clamp (bolt, nut)
Bottom Anchor Weight
Figure 15
5
Connect one end of measuring tape
(not looped) with float as shown in figure
8 and other end somewhere temporarily
to prevent fall of tape into the tank while
lowering bottom anchor.
3.
Lower bottom anchor weight along with
float through manhole up to the tank
bottom by releasing guide wires and
measuring tape gradually.
4.
Fix manhole cover at its position and
pull guide wires so that bottom anchor is
lifted about 25mm from resting surface.
See Figure 16.
Man hole cover
Bottom Anchor Weight
25mm
2.
Figure 16
1. In case of floating roof tank guide wire fixing is not required.
2. For measuring tape and spring motor setting, follow procedures
given in fresh tank installation.
4
Indicator Setting
4.1 Level Measurement
4.2 Adjustment of Indicator
(Dial & Pointer type)
By using a standard Gauge Tape, measure liquid level 2 or 3 times to obtain
average value. Then set indicator or counter at the reading thus determined. Use
certified gauge tape for accurate and reliable measurement.
After removing the indicator cover from the
gauge head loosen the cap nut. The longer
pointer can be turned freely, whereas the
shorter one can be freed by pulling it
outwards.
1.
First set the shorter pointer at the
division on the inner scale
corresponding to the two lower digits of
the liquid level (see figure 17).
Example to set readings:
1 1 1 0 mm
Higher Digits
2.
6
Set at 1/10 division for liquid level of 100 mm.
Long Pointer
1
2
3
4
Cap Nut
Example:
Long Pointer Reading = 1.1 M
= 1100 mm
Short Pointer Reading = 10 mm
Total = (1100+10) mm = 1110 mm
Lower Two Digits
Then, set the longer pointer at the
division corresponding to higher digits
plus the two lower digits (estimated by
the eye).
Short Pointer
0 10
20
30
Figure 17
4.3 Indicator Reading
Procedure
1.
First read longer pointer which gives reading in meters (each small division
being equal to 100mm).
2.
Then, read the shorter pointer which gives reading in millimeters.
3.
Add both the readings.
Figure 17 shows pointers adjusted on a reading of 1110mm.
4.4 Adjustment of Counter
Refer figure 18. After removing the counter
cover loosen dial set screw located at center
of scale dial. Then the dial can be turned
freely. By turning scale dial, adjust three
counter drums with higher three digits of the
liquid level.Then adjust scale dial so that red
index indicates the lower two digits of liquid
level. After digital counter has been set
properly, tighten the dial set screw.
Dial Set Screw
Red Index
1 4 0
mm
First Drum
Second Drum
Black Band
Third Drum
Green Band
Figure 18
Refer figure 19 showing counter reading
when digits are in the center of the window.
The Counter reads 14010mm.
90
95
4.5 Counter Reading
Procedure
1 4 0
00
05
10
mm
Reading: 1 4 0 1 0 mm
Read Digits
Read Dial
Figure 19
Refer figure 20 and 21 when digits are in
changeover position. When the red index is
on the green band, read digits lying on the
green side of the counter, see figure 20.
Green Side
Counter reads 14000 mm.
Black Side
Green Marks
0
1 4
3mm9
90
95
00
05
10
Reading: 1 4 0 0 0 mm
Read Digits
Read Dial
Figure 20
When the red arrow is on black band, read
digits lying on black side of counter, see
figure 21.
Counter reads 13998mm.
0
1 4
3mm9
90
95
00
05
10
Reading: 1 3 9 9 8 mm
Read Digits
Read Dial
Figure 21
7
5
Operation
Once the tank level gauge has been installed and reading is adjusted, allow it to run
into operating condition till the float has traveled for 2 to 3 times from low level to
high level. Cross check tank level gauge reading with gauging tape reading and
adjust tank level gauge reading once again if there is any difference in the reading.
This is necessary only at initial stage.
6
Checker Function
Refer figure 22. Operation checker is used
for confirming gauge reading. By rotating
Checker Knob, a small jerk is provided to the
indication system and the reading is noted
when pointer comes to stable position.
0
M et er s
90
4
0
M i ll i m e t
ers
10
20
80
1
30
70
Nivo Controls Pvt. Ltd.
60
1.
Turn checker knob clockwise as shown
by arrow about 90 degrees and leave it
free. Turn knob 1 or 2 times only (see
figure 22).
2.
Note the reading after the pointer has
become stable.
3
40
50
2
Checker Knob
Figure 22
7
Cranking Function
(Optional)
This attachment is provided for hoisting and
lowering the float to protect it from severe
turbulence and agitation caused by
agitators present near the float.
0
M et er s
90
4
M i ll i m e t
ers
10
80
20
70
30
1
Nivo Controls Pvt. Ltd.
Raise the float to the tank top and lock it
when the level gauge is not in use.
Raising and Lowering of the float should be
done gently otherwise it may damage gauge
head and transmitter part if mounted with
the gauge head. Refer figure 23.
0
60
3
50
40
2
Cranking Unit
Figure 23
8
Maintenance
Guidelines
This manual describes checking, repairing and troubleshooting required for
maintenance and proper performance of NIVOGAUGE MLF-1000 as well as safe
operation at site.
No particular routine maintenance is necessary for NIVOGAUGE MLF-1000 if it is
in regular operation.
8.1 Periodic Maintenance
8
Periodical checks should be performed at a frequency matched with operating
condition at site since service life of the parts are dependent on environment
conditions and frequency of level variation in tank.
Items to be checked periodically are listed below:
8.2 Troubleshooting
Check Items
Maintenance Procedure
Free movement of
sprocket wheel
After opening the rear cover of the gauge head, check each drum
for its bearing condition as well as for free movement.
Water drops or dimming on
indicator glass
Check if the indicator cover is not tightened properly. Also check if
foreign matter is caught in the packing.
Friction on sheave elbow
roller pulley
After detaching measuring tape from sheave elbow pulley, check
rollers movements & ensure that they run smoothly. Disassemble
bearings and check for wear & tear. Clean the rollers if necessary.
Liquid Seal
Ensure liquid paraffin level is maintained if liquid seal is installed.
Accumulation of liquid
inside the gauge head
Open drain plug provided at the bottom of the gauge head. Allow
the liquid to drain out completely and replace plug.
Symptom
Possible Cause
Remedy
Indicator showing
constant reading
1. Measuring Tape Broken
2. Spring Motor broken
3. Checker Jam
1. Open tank & replace tape.
2. Replace
3. After opening rear cover of
gauge head, repair or replace
checker parts
4. Replace Gear Set of Indicator
4. Transmission gear for Indicator
worn out
5. Improper setting of sprocket or
disengagement of Tape
6. Float submerged
5. Open rear cover and set tape
guide
6. Open tank and replace Float
Indicator Reading
deviates from
actually measured
level
1. Setting Disturbed
1. Measurement with Gauging
Tape affected by untrained
personnel
2. Sludge accumulation
3. Strong Wind or Improper
setting of Measuring Scale
Indication changing
frequently
1. Spring Motor deteriorated
2. Guide Wire Loose
1. Replace Spring Motor
2. Open tank and re-stretch guide
wire
3. After detaching Indicator Cover,
check Pointer Lock Nut, tighten
properly
4. Check gap between Sprocket
and Tape Guide
5. After removing Sheave Elbow
Cover, pull out and check
Measuring Tape. It may be
repaired in certain condition
otherwise replace
3. Indicator Pointer Loosened
4. Improper setting of Tape Guide
5. Measuring Tape kinked or
twisted
Checker
Inoperative
1. Setscrew of checker knob loose
2. Setscrew of spring holder loose
3. Spring deformed or broken
1. Tighten Setscrew
2. Tighten Setscrew
3. Replace Spring with Spring
Holder Assembly
9
9
Spare Parts
Minimum Stock Level to ensure uninterrupted working.
Serial No.
10
Part Name
Quantity
per Gauge Head
Installed
1.
Rear Cover Cork Gasket
1
2.
Neoprene Blind Packing
1
3.
Spring Motor
1
4.
Neoprene U Channel Indicator Cover
1
5.
Pointer Kit
1
6.
Indicator Cover Screws M5325
4
7.
Indicator Cover Glass
1
8.
Checker Knob
1
9.
Measuring Tape
1
10.
Float
1
WARRANTY
Instruments are strictly supplied as per the purchase order specifications,
standard guarantee term is for twelve months from the date of commissioning or
eighteen months from the date of despatch whichever is earlier. Guarantee term is
strictly for any manufacturing fault, i.e. any defect is discovered in terms of material
and workmanship. We undertake to make good the defect at our own expenses,
provided notice is given to us as soon as it is discovered and the instrument is
forwarded to our factory insured and freight paid and with seals unbroken. Our
responsibility in all cases is limited to the cost of removing the defect in the
instrument itself. This guarantee is given to our customers and does not extend to
third parties, nor does it apply to defects caused by wear and tear, abnormal
condition of working, accident, misuse or neglect.
CUSTOMER
SERVICE
For any clarification or assistance please contact our nearest service centre.
SERVICE CENTERS
Ajmer
Toshniwal Process Instruments Pvt. Ltd.
Mahatma Gandhi Marg
Ajmer 305 001
Ph: 0145 420506 Fax: 0145 420505
Ahmedabad
Toshbro Pvt. Ltd.
E-20, Capital Commercial Center
Ashram Road
Ahmedabad 380 009
Ph: 079 6578145 Fax: 079 6577941
Bangalore
Toshbro Pvt. Ltd.
32, 9th A Cross
West of Chord Road
2nd Stage, Bangalore 560 086
Ph: 080 3496143 Fax: 080 3496143
Baroda
Toshbro Pvt. Ltd.
2-A Kirti Towers
Near Kirti Mandir
Tilak Road, Baroda 390 001
Ph: 0265 422768/421668 Fax: 0265 428057
Calcutta
Toshbro Pvt. Ltd.
Nichitpur House
6 Andul Raj Road, 4th Floor
Calcutta 700 026
Ph: 033 4854314 Fax: 033 4854314
Chennai
Toshbro Pvt. Ltd.
16-A, Wellingdon Estate
24 Commander-IN-Chief Road
Chennai 600 105
Ph: 044 8276338/8263146 Fax: 044 8276338
Hyderabad
Toshbro Pvt. Ltd.
D. No. 7-1-24/A, Greenlands
Near Greenwoods Nursery School
Ameerpet, Hyderabad 500 016
Ph: 040 3734906/3735456 Fax: 040 3731589
Mumbai
Toshbro Limited
15 Mahal Industrial Estate
Mahakali Caves Road, Chakala, MIDC
Andheri (East), Mumbai-400 093
Ph: 022 8373111/8371695 Fax: 022 8364828
New Delhi
Toshbro Pvt. Ltd.
E-1, 602, ABCD Deepshikha
8 Rajendra Place
New Delhi 110 008
Ph: 011 5772017/5752464 Fax: 011 5766222
Pune
Toshbro Pvt. Ltd.
MP J Chambers, 2nd Floor
Room No. 9 & 10, Bombay Pune Road
Pune 411 003
Ph: 0212 5810905 Fax: 0212 5817606
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