BROOKFIELD MODEL BF35
Installation, Operation and Maintenance Instructions
Manual No.
M13-10000
TABLE OF CONTENTS
Section 1: Introduction .....................................................................................................7
Description ...................................................................................................................7
Section 2: Specications .................................................................................................8
Section 3: Safety .............................................................................................................11
Electrical Requirements .............................................................................................12
Environment Conditions .............................................................................................12
Installations ................................................................................................................12
Equipment Operations ...............................................................................................13
Section 4: Setup ..............................................................................................................14
Section 5: Calibration .....................................................................................................15
Procedure ..................................................................................................................15
Section 6: Operation .......................................................................................................17
Measuring Viscosity ...................................................................................................17
Measuring Gel Strength .............................................................................................17
API T esting .................................................................................................................17
Section 7: Calculations ..................................................................................................18
Section 8: Disassembly ..................................................................................................19
Section 9: Maintenance ..................................................................................................20
The information in this document is believed to be accurate and reliable. However, Brookeld
Engineering Laboratories, Incorporated, cannot accept any nancial or other responsibilities that may
result from the use of this information. No warranties are granted or extended by this document.
Brookeld Engineering Laboratories, Incorporated reserves the right to change any or all information
contained herein without prior written notice. Revisions may be issued at the time of such changes
and/or deletions.
Any duplication of this manual or any of its parts without expressed written permission from Brookeld
Engineering Laboratories, Incorporated is strictly prohibited.
Any correspondence regarding this document should be forwarded to:
Brookeld Engineering Laboratories, Incorporated
Process V iscometer Division
11 Commerce Boulevard
Middleboro, Massachusetts 02346
U.S.A.
Telephone: (508) 946-6200
FAX: (508) 946-6262
Internet: http://www.brookeldengineering.com
The following Brookeld Engineering Laboratories, Incorporated trademarks and service marks may
appear in this document:
All other trademarks or registered trademarks are the property of their respective holders.
Copyright© 2005 Brookeld Engineering Laboratories, Incorporated Printed in U.S.A.
Introduction
Description
Section 1 - Introduction
The BF35 Viscometer is extensively used worldwide in both the eld and
laboratory for the precise measurement of rheological properties of uids.
The BF35 Viscometer determines the ow characteristics of oils and drilling uids
in terms of shear rate and shear stress over various time and temperature ranges
at atmospheric pressure. Speeds are easily changed with a control knob, and
shear stress values are displayed on a lighted magnied dial for ease of reading.
The viscometer’s motor RPM is continuously monitored and automatically
adjusted by the Brookeld Pulse-Power electronic speed regulator to maintain a
constant shear rate under varying input power and drilling uid shear conditions.
The eight precisely regulated test speeds (shear rates in RPM) are as follows: 3
(Gel), 6, 30, 60, 100, 200, 300, and 600. A higher stirring speed is also provided.
Speeds may be changed with a control knob selection, without stopping the motor .
The BF35 is suitable for both eld and laboratory use and uses a motor-driven
electronic package to provide drilling uid engineers with an extremely accurate
and versatile tool. The BF35 operates from a 13 - 16 VDC power source. The
electronic regulator continuously monitors and automatically adjusts the rotational
speed to maintain a constant shear rate under varying uid shear conditions and
input power variations that are commonly found on-site.
Brookeld Engineering Labs., Inc. Page 7 Manual No. M13-10000
Specications
Viscometer Specications
Instrument Geometry True Couette Coaxial Cylinder
Speed Accuracy (RPM) .001
Section 2 - Specications
Motor Speeds (RPM)
Readout Direct Dial
Power Requirements 13 - 16 VDC
Weight (kg) 6.0
Dimensions (cm) 15.2 x 17.8 x 40.6
Shipping Weight (kg) 20.4
Shipping Details (cm) 55.9 x 25.4 x 40.6
Range of Measurement for BF35
Rotor - Bob R1B1 R1B2 R1B3 R1B4
Rotor Radius, RR, (cm) 1.8415 1.8415 1.8415 1.8415
Bob Radius, RB, (cm) 1.7245 1.2276 0.8622 0.8622
Bob Height, L, (cm) 3.8 3.8 3.8 1.9
8 Fixed Speeds (600, 300, 200, 100, 60,
30, 6, and 3)
Shear Gap, (cm) 0.117 0.6139 0.9793 0.9793
R Ratio, RB/RR 0.9365 0.666 0.468 0.468
Max. Shear Stress, SS
(Dyne / cm
F 0.2 (Green) 330 651 1320 2644
F 0.5 (Yellow) 840 1657 3359 6730
F 1.0 (Blue) 1680 3314 6717 13460
F 2.0 (Red) 3360 6629 13435 26921
F 3.0 (Purple) 5040 9943 20152 40381
F 4.0 (White) 6720 13257 26870 53841
F 5.0 (Black) 8400 16571 33587 67302
F 6.0 (Orange) 16800 33143 67175 134603
Brookeld Engineering Labs., Inc. Page 8 Manual No. M13-10000
2
)
MAX
,
R1B1 R1B2 R1B3 R1B4
Shear Rate Range R1B1 R1B2 R1B3 R1B4
Shear Rate Constant, K
-1
per RPM)
(sec
Shear Rate (sec-1 or 1/s)
3 RPM
6 RPM 10.21 2.26 1.61 1.61
30 RPM 51.07 11.31 8.05 8.05
60 RPM 102.14 22.62 16.09 16.09
100 RPM 170.23 37.70 26.82 26.82
200 RPM 340.46 75.40 53.64 53.64
300 RPM 510.69 113.10 80.46 80.46
600 RPM 1021.38 226.20 160.92 160.92
Viscosity Ranges
Minimum V iscosity
<a>
<b>
@600 RPM
Maximum V iscosity
<d>
@0.01 RPM
,
R
1.7023 0.3770 0.2682 0.2682
5.11 1.13 0.80 0.80
R1B1 R1B2 R1B3 R1B4
<c>
0.5
4.5 12.7 25
10,000,000 89,000,000 255,000,000 500,000,000
<a> Compute for standard Torsion Spring (F 1.0). For other torsion springs, multiply by F factor.
<b> Lower viscosities can be measured by the Model 900, however one must take into account the
effect of bearing drag, Taylor vortices, zero offset, etc. when looking at the expected accuracy of
the reading.
<c> For practical purposes, the minimum viscosity is limited to 0.5 cP due to Taylor vortices.
<d> Maximum viscosity is based on Maximum Shear Stress and Minimum Shear Rate (RPM).
However, due to practical and physical limitations, it may be difcult to take these measurements.
Viscometer Conversions
To convert from units on left side to units on top, multiply by factor @ intercept
Centipoise (cP) Poise (P) g/(cm*s) (mN*s)m2mPa*s (lb*s) 100 ft
Centipoise (cP) 1 0.01 0.01 1 1 0.002088
Poise (P) 100 1 1 100 100 0.2088
g/(cm*s) 100 1 1 100 100 0.2088
(mN*s)m
2
1 0.01 0.01 1 1 0.002088
2
mPa*s 1 0.01 0.01 1 1 0.002088
(lb*s) 100 ft
Brookeld Engineering Labs., Inc. Page 9 Manual No. M13-10000
2
478.93 4.789 4.789 478.93 478.93 1
Shear Stress Conversions
To convert from units on left side to units on top, multiply by factor @ intercept
Dyne/cm
Dyne/cm
2
2
Pa lb/100ft
1 0.1 0.2084 0.002084 0.1957
2
lb/ft
2
DR
Pa 10 1 2.084 0.02084 1.957
lb/100ft
2
lb/ft
2
4.788 0.4788 1 0.01 0.939
478.8 47.88 100 1 93.9
DR 5.107 0.5107 1.065 0.01065 1
What Bob and Spring Should I Use?
There is often confusion or misunderstanding about what a viscometer can actually measure. For
example, a viscometer with an R1B1 F1 combination can measure water fairly well at 100 RPM
and higher, but at 3 RPM, the readings would be shaky at best. While on the other hand, a linear
uid with a viscosity of 15000, could not get past 6 RPM with the same combination.
To estimate which spring might be best, use the formula below to calculate a Minimum Spring
factor, where one establishes the maximum RPM the uid is going to be tested at, as well as what
the expected “Apparent Viscosity” of the uid at that RPM. If the Factor comes out as .87, then an
F 1.0 spring should be used. If it comes out as .16, then an F 0.2 spring would be best. To cover all
ranges, it may be necessary to use more than one spring.
Minimum Spring Factor (F) =
Bob (F)
R1B1 1
R1B2 8.9
R1B3 25.4
R1B4 50.7
RPM(max) * A V(max)
BOB(F)*90000
Brookeld Engineering Labs., Inc. Page 10 Manual No. M13-10000
Safety
Section 3 - Safety
Explanation of Symbols
Caution: Risk of Danger - This symbol directs the operator to consult
the instruction manual for safety related warnings. (ISO-7000-0434)
Whenever this symbol is used on the equipment, the user must
consult the manual to determine the nature of the hazard and any
actions which have to be taken.
Fuse: This is the internationally recognized symbol for a user-
replaceable fuse. This symbol will be followed by information
required to guide the user to choose the proper replacement fuse.
Direct Current (DC): This symbol indicates an input (or output)
that is direct current only. (IEC 60417-5013)
Note: This symbol will indicate important notes and helpful hints
for the operation of the equipment.
Polarity: This symbol indicates that the equipment receives positive
voltage on the center pin of the connector and the return voltage is
on the outer case.
Tip: This symbol is used to identify operational information and best
practices to obtain the most reliable data.
Caution: Note - This symbol is used to indicate statements in the
manual which warn against actions which may cause damage to the
equipment during routine service or maintenance.
Brookeld Engineering Labs., Inc. Page 11 Manual No. M13-10000
Electrical Requirements
The BF35 Viscometer is to be powered by a DC power source capable of
providing between 13 and 16 volts DC. The equipment is current limited to 4
amps by a user-replaceable fuse. However, we suggest that the power supply
be current limited to less than 4 amps to provide additional protection to the
equipment.
Power (On/Off) Switch
When connecting the equipment to your power source, make sure that the 13 - 16
VDC is connected to the center pin of the connector.
The equipment is supplied with a user-replaceable fuse. This fuse must only be
replaced by a 250-volt, 4-amp, time-delayed fuse.
Environment Conditions
The equipment is designed for use in normal environmental conditions:
- Indoors
- At or below an altitude of 2,000 m (6,562 ft)
- In temperatures between 5˚ and 40˚C (41˚ - 104˚F)
- With a maximum relative humidity of 80% for temperatures up to 31˚C
(88˚F) decreasing linearly to 50% relative humidity at 40˚C (104˚F)
- This equipment has not been rated according to IEC 60529
Input Connector:
13 - 16 VDC Power
Inlet / Emergency
Disconnect Device
Installations
The BF35 V iscometer should be used in a location where it will not be subjected
to excessive moisture. It should be placed on a at, stable surface in a well-
ventilated environment.
Brookeld Engineering Labs., Inc. Page 12 Manual No. M13-10000
Caution - Risk of Danger: This equipment produces sound pressure in excess
of 85 dBA. Protective measures (such as hearing protection, noise-reducing
bafes, or a hood) should be considered.
Equipment Operation
Caution - Risk of Danger: The (13 - 16 VDC) power cord and the DC inlet are
the emergency disconnect devices. Do not position the equipment such that it is
difcult to operate the emergency disconnect devices.
Caution - Risk of Danger: In normal operation, this equipment may liberate the
potentially poisonous gasses listed below . However, the list below is dependent
upon the chemical makeup of the sample uids presented for testing. Care should
be taken to ensure that: no unexpected or anomalous chemicals are contained
or added to the test samples; the test environment is adequately ventilated; and,
when necessary, appropriate personal protective equipment is employed.
- Hydrogen Sulde (H
- Methane (CH
)
4
- Carbon Dioxide (CO
- Sulfur Dioxide (SO
S)
2
)
2
)
2
Caution - Risk of Danger: The samples presented for testing may contain
ammable substances. The following risk-reduction procedures must be followed
to ensure the safe operation of the equipment.
- Always use in a well-ventilated area.
- Keep away from open ames.
Caution - Risk of Danger: If this equipment is operated in a manner not specied
by the manufacturer (Brookeld), the protections provided by the equipment
may be impaired.
Caution - Risk of Danger: This equipment may operate unexpectedly if the
equipment is energized when the Speed Selector Knob and Power (On/Off) Switch
are left in the “On” position. Care should be taken to ensure both switches are in
the “Off” position prior to energizing the equipment. Also, care should be taken
to ensure that the Speed Selector Knob is in the “Off” position prior to turning
the Power (On/Off) Switch to the “On” position.
Speed Selector Knob
Brookeld Engineering Labs., Inc. Page 13 Manual No. M13-10000
Setup
Section 4 - Setup
1. Connect the instrument to a 13 - 16 VDC, current-limited power source.
2. With the instrument turned of f, place the splash guard onto the bob shaft with
the short tube end pointed up towards the bearings. Push up.
3. Screw on the appropriate bob with the tapered end up towards the splash guard.
4. Place the sleeve onto the rotor over the bob. The threads assure the rotor will
attach evenly and uniformly each and every time.
5. The power switch is located on the back panel. Turn the unit on.
6. Place a properly prepared sample of test uid in a sample cup and immerse
the rotor sleeve exactly to the ll line on the sleeve by raising the platform.
Tighten the lock nut on the platform.
Rotor
Splash Guard
Bob
Sleeve
Platform
Brookeld Engineering Labs., Inc. Page 14 Manual No. M13-10000
Section 5 - Calibration
Calibration
The BF35 Viscometer can lose calibration while in service if the bob shaft
bearings become contaminated or if the bob shaft itself is bent. If the dial does
not read zero when it should or if there is excessive dial deection when the main
shaft is turning, this may indicate that the bob shaft bearings are sticking. If the
spring appears to be non-linear, the bob shaft may be bent. Your viscometer will
require servicing if it exhibits any of these symptoms.
According to API Recommended Practice 10B-2, viscometers being used for
testing well cement should be calibrated quarterly . API Recommended Practice
13B-1 and 13B-2 specify viscometers being used for drilling uids should be
checked monthly.
Procedure
1. Choose the certied calibration uid using the temperature-viscosity chart
supplied with the calibration uid to cover the viscosity range of interest.
Make sure the lot number on the chart matches the lot number on the uid
container. Each lot of standard uid is individually certied. The viscosity
will normally vary slightly from lot to lot.
2. Clean and dry the viscometer bob, sleeve, and cup. Place the viscometer
and the calibration uid side-by-side on the counter top in a room with a
reasonably constant temperature (variation of less the 5˚F ± 2.5˚F). Allow
the viscometer and the uid to stand at least two hours to equilibrate.
3. Operate the viscometer in air for two to four minutes to loosen up the
bearings and gears. Observe the rotor sleeve for excessive wobbling and
replace if necessary.
4. Fill the cup to the scribed line with calibration uid and place it on the
viscometer stage. Move the stage upward until the uid level is to the ll
line on the sleeve.
Fill Line
Viscometer Sleeve
5. Place a thermometer capable of ± 0.2˚F (0.1˚C) into the uid and hold or
tape it in place to prevent breakage. Operate the viscometer at a low speed
Brookeld Engineering Labs., Inc. Page 15 Manual No. M13-10000
setting until the thermometer reading becomes stable to within ± 0.2˚F
(0.1˚C) per seconds. Note and record the temperature reading.
6. Once the temperature has stabilized, operate the viscometer at 600 RPM
and then at 300 RPM. Note and record the dial readings to the nearest 0.5
dial unit.
7. Using the temperature-viscosity chart supplied with the calibration uid,
determine the certied viscosity to the nearest 0.5 centipoise.
a. Compare at 300 RPM reading to standard viscosity and record the
deviation plus or minus.
b. Divide the 600 RPM dial reading by 1.98, compare that to standard
viscosity, and record the deviation plus or minus.
8. Deviations exceeding 1.5 dial units are not acceptable. If the deviation
exceeds this tolerance, the viscometer will require adjustments or calibration
by a qualied technician.
9. Record the viscometer serial number, date, and deviation. Mark on the
viscometer the date of calibration and a general indication of the calibration
check status.
Brookeld Engineering Labs., Inc. Page 16 Manual No. M13-10000
Section 6 - Operation
Operation
Measuring Viscosity:
1. Mix the sample on the “STIR” setting for 10 seconds while heating or cooling
the uid. Monitor the temperature with a thermometer. Continue to mix until
the sample reaches the target temperature.
2. Rotate the knob to one of the speed settings. When the dial reading stabilizes,
record the reading and the temperature. Repeat this step for any other speeds
that your test requires.
Always start with the higher RPM and work your way down to the lowest RPM.
For example, if you need readings at 100 RPM, 200 RPM, and 300 RPM, record
the measurement at 300 RPM rst, then 200 RPM, then 100 RPM, then gel
strengths (if necessary).
Measuring Gel Strength:
1. Mix the sample on the “STIR” setting for 10 minutes.
2. Rotate the knob to “GEL” and immediately shut off the power.
3. As soon as the sleeve stops rotating, wait 10 seconds and turn the power back
on while looking at the dial. Record the maximum dial deection before the gel
breaks. This is the 10 second gel strength.
When measuring gel properties, the dial does not have to return to zero during
the quiescent period. Therefore, it should not be forced back to the zero setting
if it does not freely do so. When determining the maximum dial deection, no
allowance needs to be made if the dial did not start at zero. Only the maximum
dial deection is of interest. Rheological properties and characteristics of the
sample will determine if the dial returns to zero during the quiescent periods of
the gel measurements.
4. For the 10 minute gel strength, re-stir the uid and wait 10 minutes before
recording the maximum dial deection.
API Testing:
1. Mix the sample on the “STIR” setting for 10 seconds.
2. Set the speed to 600 RPM. Wait for the reading to stabilize and then record the
dial reading and temperature.
3. Set the speed at 300 RPM. Wait for the reading to stabilize and then record the
dial reading and temperature.
4. Stir the sample again for 10 seconds.
5. Set the speed to “GEL” and immediately shut off the power.
6. As soon as the sleeve stops rotating, wait 10 seconds and turn the power on while
looking at the dial. Record the maximum dial deection before the gel breaks.
This is the 10 second gel strength.
7. For the 10 minutes gel strength, re-stir the uid and wait 10 minutes before
recording the maximum dial deection.
Brookeld Engineering Labs., Inc. Page 17 Manual No. M13-10000
Calculations
Section 7 - Calculations
Plastic Viscosity (PV), cP = 600 RPM reading - 300 RPM reading
Yield Point (YP), lb./100 ft
2
= 300 RPM reading - Plastic Viscosity (PV)
Apparent Viscosity (AV), cP = 600 RPM reading / 2
Gel Strength, 10 second, lb./100 ft
Gel Strength, 10 minute, lb./100 ft
2
= the maximum dial deection after 10 sec.
2
= the maximum dial deection after 10 min.
Brookeld Engineering Labs., Inc. Page 18 Manual No. M13-10000
Disassembly
Section 8 - Disassembly
Clean the viscometer after every test.
1. Remove the sleeve from the rotor.
2. Remove the bob.
3. Once the bob is removed, remove the splash guard and wipe down the bob shaft.
Clean all removed parts with soap and water and dry them thoroughly.
Keep the instrument upright at all times, especially when cleaning so that
water does not get into the bearings.
Brookeld Engineering Labs., Inc. Page 19 Manual No. M13-10000
Maintenance
Section 9 - Maintenance
From time to time, the bearings will need to be changed. Complete the following to
determine if it is time to perform this maintenance procedure:
1. The viscometer should have a zero dial reading when placed in an upright position
with the sleeve not immersed in uid prior to running tests.
2. With the instrument in this position, rotate the sleeve at 600 RPM. The dial
reading in air should not exceed one.
3. Place water in a suitable container and immerse the rotor sleeve to the ll line.
4. Rotate the sleeve at 600 RPM. The dial reading in water should be between 1.5
and 3.0.
5. At 300 RPM, the dial reading in water should be between 0.5 and 2.0.
If the viscometer fails to pass any one of the above tests, the bearings are bad and should
be replaced by a qualied instrument technician.
Bob Shaft Bearing and Torsion Spring Replacement:
Tools Required:
Allen Wrench, 1/16”
Torsion Spring Removal Tool
Retainer Ring Pliers (small)
External Retainer Ring Pliers
1. Unplug the power supply and remove the sleeve and bob.
2. With the appropriate allen wrench, loosen the set screw in the speed control
knob. Remove the speed control knob from the unit.
3. Remove all four at head screws on the outer housing cover and gently lift the
cover upward.
4. Use an allen wrench to loosen the set screw (one turn counter-clockwise) from
the aluminum bushing located inside the torsion spring. The set screw is located
at the top of the aluminum clamp sleeve used for the torsion spring.
5. Loosen the two screws and remove the stop block.
6. Loosen the top set screw (one turn counter-clockwise) on the dial.
7. Gently lift up on the torsion spring to remove it from the aluminum clamp sleeve
and dial.
Do not stretch the torsion spring.
Brookeld Engineering Labs., Inc. Page 20 Manual No. M13-10000
If you are replacing only the torsion spring, discard the old spring, and skip to
step 20 to complete the process.
Set Screws (Step 5)
Set Screw (Step 4)
Bridge
Dial
Brass Bearing Mount
8. Remove the four screws from the bridge and lay it gently to the right side.
Aluminum Clamp Sleeve
Stop Block
Torsion Spring
Set Screw (Step 6)
Do not touch the encoder that encircles the ywheel.
9. Loosen the set screw (one turn counter-clockwise) on the bottom of the dial and
pull down on the bob shaft to remove them both.
10. Remove the two screws on the brass bearing mount (upper bearing). Hold the
upper brass bearing mount by the hand for easier access to the retainer ring and
bearing.
Be careful not to damage the pins.
Set Screw
Upper Bearing
Retainer Clip
Brass Bearing Mount
Set Screw
11. The upper bearing is located inside the brass bearing mount. Use the retainer
ring pliers to remove the retainer ring. Push the bearing upwards to remove the
upper bearing from the brass bearing mount.
12. Use surgical gloves to insert a new upper bearing into the brass bearing mount
and replace the retainer ring with the retaining ring pliers.
Brookeld Engineering Labs., Inc. Page 21 Manual No. M13-10000
Do not touch the bearing with bare hands. Dirt, oils, and other contaminants
can damage the bearing.
13. Replace the brass bearing mount back onto the two pins and tighten the two
screws.
14. Remove the Splash Guard, loosen the set screw on the lower brass bearing shield
(one turn counter-clockwise), and slide the lower bearing down the bob shaft to
remove all three components.
15. Use surgical gloves to apply a new lower bearing onto the bob shaft.
16. Install the lower brass bearing shield and tighten the set screw . Slide the splash
guard back up the bob until it touches the lower brass bearing shield.
The bearing should be able to free spin for up to two minutes. If it does not,
replace it with a new bearing.
Torsion Spring
Brass Bearing
Mount
Bob Shaft
Bearing Shield
Lower Bearing
Splash Guard
17. Slide the bob shaft up through the upper brass bearing mount. T urn the bob shaft
in the direction that allows the “Flat” located at the top of the bob shaft to be
positioned towards you.
18. Align the bottom set screw on the dial with the “Flat” on the bob shaft and tighten
rmly. Make sure the set screws are perpendicular to the tip of the bob shaft.
The bob shaft should rotate smoothly without any noise.
19. Replace the bridge being careful not to touch, or bend the encoder . Tighten the
four screws.
Brookeld Engineering Labs., Inc. Page 22 Manual No. M13-10000
20. Gently slide the torsion spring through the aluminum clamp sleeve and into the
dial. Make sure the bottom of the torsion spring is seated properly inside the dial.
Tighten the set screw located at the top of the dial to secure the torsion spring.
21. Replace the stop block and the two screws. Make sure that the zero dial reading
is aligned with the ll on the stop block.
22. Press down on the torsion spring until it is ush with the Aluminum Clamp
Sleeve and tighten the set screw.
23. Replace the bob and sleeve.
24. Re-attach the main housing cover and re-calibrate.
Brookeld Engineering Labs., Inc. Page 23 Manual No. M13-10000
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