Knew Value Sentinel B User manual

Sentinel Operating Manual
Model B
rev: January 29, 2020

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SENTINEL MODEL B-2 OVERVIEW ....................................................................................................................................... 3
MODEL B-2 TOUR ............................................................................................................................................................... 4
SENTINEL INITIAL INSTALLATION ........................................................................................................................................ 6
SAFETY FEATURES & SAFE OPERATION ............................................................................................................................... 7
MODEL B-2 OVERVIEW ....................................................................................................................................................... 8
EXCHANGER TUBE CHANGE & INSTALLATION ..................................................................................................................... 9
START UP ......................................................................................................................................................................... 11
ONGOING MAINTENANCE & BEST PRACTICES .................................................................................................................. 13
TROUBLESHOOTING ......................................................................................................................................................... 14
SUPPLIES & SERVICE ......................................................................................................................................................... 15

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Sentinel Model B-2 Overview
Overview Details:
NEMA4 Carbon Steel, Windowless enclosure.
Standards: UL 508 Type 3R, 4, and 12 CSA Type 3R, 4, and 12 Complies with NEMA Type 3R, 4, and 12 IEC 60529, IP66
Dimensions & Weight:
Width – 30 inches, Height – 30 inches, Depth – 12 inches
Weight – 125-175 lbs (dependent upon configuration).
Site requirements: Standard 120vac 20a power, cooling water cooling water sample of at least 6 gpm and return/drain.
Note: Cooling Tower supply water preferred.
Optional configurations (not shown):
- 240vac
- Air Purge

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Model B-2 Tour
1) Power plug – this is a marine all weather, twist power plug. It is used to connect the Sentinel to the electrical circuit.
2) Cooling Water inlet and outlet. Connection is ½” male NPT threaded bulkhead fittings.
3) Exchangers. Two, single tube, annular test heat exchangers. Each with a 1-inch, clear polycarbonate shell mounted in
the bottom of the enclosure. Exchanger #1 is in the rear and Exchanger #2 is in the front.
4) Cooling Water Inlet Flow Meters. Cooling water enters from the right side of the enclosure, passing a temperature
indicator to measure the cooling water inlet temperature. The inlet is split into two streams and then passes through
the flow meters to measure velocities for each exchanger.
5) Cooling Water Flow Valves. Located on the right side of the enclosure, on the cooling water outlet side of the
exchangers. These are used to set the velocities of each exchanger. Open valves are parallel to the valve body. Closed
valves are perpendicular to the valve body.
6) Cooling Water Exit Temperature Indicator. Located on the exit of each exchanger to measure the temperature of the
cooling water.

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7) Breaker Panel. This is the main power control and mount for limit devices and display.
8) Breakers:
o Data: Controls power to the Data Logger, Limit Controllers, Camera, and Light
o HTR 1 & HTR 2: Controls power to each immersion heater in the two heaters.
9) Limit Controls: Set to limit heater core temperature to a max of 500º F. Requires manual reset if limit reached.
Displays the core temperature of each heater during normal operation.
10) Heater Rheostats: Used to set power to each 1200 watt heater inserted through the two exchangers.
11) Data Logger Display. Shows velocities and skin temperatures for each exchanger, in addition to unit s/n, and connected
components.
12) Data Logger – this computer collects and transmit data and photos.
13) Modem – provides a cell phone connection to upload velocity, skin temperature and photos.
14) USB thumb drive – collects a local copy of velocity, skin temperature and photos.
15) Camera. Captures photos of the exchangers and cooling water results.
16) Camera Light. Utilized to enable pictures of the exchangers while enclosure door is shut.

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Sentinel Initial Installation
In order to prepare your Sentinel for operation the following steps must be taken:
1) Connect adequate power to the unit. Sentinel Model B-2 requires 120vac, 20 amps power. A 30amp inlet plug is
provided and must be wired prior to installation.
2) Connect Cooling Water inlet to adequate sample line. Approximately 6 gpm.
3) Connect Cooling Water outlet to return cooling water to outlet or drain.
4) Connect Process Fill Column & Process Vent tubing to the exterior of unit.
5) Place or mount the unit to a stable location.
Power Inlet Plug Wiring Instructions:
Warning: To prevent electrocution make sure the cable is not connected to a power source before installing the plug or
connector.
Failure to comply with the following instructions could cause an electrical failure or fire.
1) Check to see the rating on the plug or connector is correct for the installation.
2) Select a cable of suitable amp capacity, service, and temperature rating. The plugs and connectors are designed for
use with round jacketed, hard usage cable (S-type, 8-3AWG.)
3) Remove the housing by loosening the three screws on the face of the device and slide it over the cable. If a
weather resistant boot is used, slide this over the cable before the housing. Strip the outer jacket of the cord 1.25”
and 5/8” of the inner insulation to expose the copper wire. Make sure the wire is clean and a bright copper color.
If necessary, cut back the wire until clean wire is uncovered. Do not solder the ends of the wires.
4) Insert all the wires into the proper color coded terminal pockets.
5) Tighten the terminal screws to 20 in-lbs torque. Make certain there is no wire insulation clamped inside any
terminal and there are no stray wire strands outside the terminals.
6) By alternating between the two screws, tighten the strain relief screws to 14 in-lbs torque so the strain relief is
even and securely grips the cable jacket.
7) Slide the housing over the plug or connector body and tighten the two assembly screws.
8) If a weather resistant boot is used, slide that over the complete assembly.
Prior to connecting the plug to the unit, ensure that all the breakers are in the off position and cooling water is blocked off
from the supply stream.
Cooling Water Inlet & Outlet Instructions:
Sentinel requires a cooling water sample line and drain. Optimal cooling water supply from the cooling tower is 6-10gpm.
Please contact us if you have a supply line that is below 6gpm. A return sample sent to the skid will assist achieving desired
higher skin temperatures due to the elevated heat. The sample should be as representative as possible, so the actual
performance of the cooling water can be monitored. The connection to the bulkhead for the cooling water inlet and outlet
is ½” Male NPT.
Additional cooling water items to consider:
- Ensure the sample line is not too long so the chlorine residual is not depleted by the time it reaches the Sentinel.
- Make sure that the pressure is not too low due to line loss. Low pressure can often be resolved with a common
hardware store booster pump, though normally only required in unusual circumstances.
- If the cooling water has debris in it, you likely will need a strainer. We have successfully utilized ¾” poly strainers
(80 mesh - 150psi) with the operation of the Sentinel.
The cooling water drain from the Sentinel can be routed back to the cooling tower or any other drain. Care should be
taken to provide an unobstructed flow from the unit to ensure adequate cooling water flow and associated velocity in the
exchangers.

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Safety Features & Safe Operation
Before using, please read and fully understand the risks associated with normal operation of Sentinel. Used improperly
there is a risk of electrical shock and burns from heated surfaces or heated water.
The operation of Sentinel is not a “plug & play” device. It requires a basic mechanical aptitude to use it successfully to
monitor a cooling water system’s performance. If it is not set up properly during start-up, it will fail, and your evaluation
will be interrupted. When operated properly, this tool provides continuous performance monitoring for years with only
tube replacements and minor maintenance. If ignored or tampered with, it will fail.
IMPORTANT: Before touching any of these surfaces, turn off all heater breakers currently on, leaving the cooling water
flowing. You will know that the exchangers are sufficiently cooled when the temperature readings on the limit controllers
displays under 100 degrees
IMPORTANT: The temperature limit controllers are set to keep the heaters from going over 500˚F. This will happen if
fluid is lost in the process chamber or cooling water flow is lost. They must be manually reset if this happens. For more
information see our troubleshooting section.

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Model B-2 Overview
Sentinel test heat exchanger consists of two annular exchangers used to model skin temperature and velocity of critical
exchangers in the process and cooling water system being monitored.
It is designed to evaluate cooling water performance and to allow online, real time visual observation of scale, corrosion
and bacteria on selected metallurgy. Data is collected from the Sentinel along with photos of the actual results inside the
exchangers and transmitted to a server and recorded locally on a thumb drive. It is important to note we do not attempt to
model an exchanger exactly on both the process and cooling water sides. Sentinel is designed to model the surface area of
the metallurgy of your choice, using the plant’s actual cooling water and a simulated process of heated water that has been
treated to insure it is a non-event from the inside of the tube specimen.
Sentinel controls are easy to understand. Before starting, ensure you are familiar with where the shutoff valves are, both
internally and on your CW supply line. We suggest a main CW shut off on the outside of the skid.
The exchangers are “The Heart of the Sentinel”. These are your annular heat exchangers that give the value of being able
to visually see the quality of your treatment results or help identify potential problems. These exchangers are explained in
detail later in this manual.
The core temperature of the heater elements are monitored by the limit controllers. These devices are set for a maximum
of 500 deg F at which point they shut off and require human reset to be restarted.
The cooling water results are visual, just like an inspection during a turnaround or outage. However, unlike a turnaround or
outage, these results can be realized immediately, as if you have a window to your heat exchanger. These results will
directly correlate to your heat exchanger. The below pictures represent actual results as observed from a metallurgic
analysis of Sentinel tube specimens.

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Exchanger Tube Change & Installation
Exchanger Removal:
When the tube is changed the skid must be turned off. If you are removing the tubes immediately following an exposure
period, please refer to the safety note intended to prevent being burned. The water inside the process chamber will leak
out of the end you first loosen. For this reason, there are drain holes at the bottom of the box. The exchangers are each
shipped with an un-weighed, temporary tube specimen.
To complete this process, it is helpful having the following tools:
7” Channel Locks
Adjustable Wrench
7/8th-inch wrench (optional)
11/16th-inch wrench (optional)
***IMPORTANT***
When you get to Step 8 (or you get over-zealous at any point in these step-by-step instructions), under no circumstances,
should you pull the tube specimen through one of the ½” fittings. This will scrape off all the deposits, and other material
from the surface of the specimen, that are on the tube, and you will not be able to sample it. The scraping off of deposits
makes accurate before/after pictures impossible. Metallurgists prefer the tube specimens to arrive at the lab dirty, so they
can observe the deposits and assist in determining the corrosion mechanism.
Step 1: First turn off only the heater breaker(s) and allow the cooling water to cool off the internal process chamber, or
you are going to burn yourself. When the temperature indicated on the limit controllers is 100 degrees or below, it is safe
to proceed to Step 2.
Step 2: Turn off the “Data/Device” breaker, unplug the heaters from their respective heater outlets, and turn off the
cooling water to the skid. Sentinel does not come with a master cooling water inlet valve. This is typically provided in
tandem with the supply stream. If the supply stream shutoff is not done, cooling water will be sprayed throughout the skid
as you begin to open lines to remove the exchangers.
Step 3: Remove the hoses from the exchangers by loosening the ½” compression fitting on the branch of each 1-inch tee.
They are labeled so don’t worry about being able to put them on the correct location following this step. You may also
trace them from their flowmeters to their respective exchangers. Please note that the valves used to control flow of
cooling water through the exchangers are on the outlet of the exchangers to ensure a liquid full condition in the
exchangers, thus they are not intended to shut off the entire cooling water supply to the Sentinel.
Step 4: Completely loosen the two ½” fittings on both the left and right respectively of the 1” Tee’s and slide them off the
end of the tube specimen. The water from the process chamber will come out at this time.
Step 5: Remove the uni-strut clamps and take the entire exchanger out of the Sentinel by sliding the immersion heater out
of the internal chamber of the tube specimen. As a best practice, we recommend putting the bolt back through the clamp,

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securing the nut and putting each clamp set on top of Sentinel enclosure so you always know where they are during
reinstallation.
Step 6: On the left 1-inch tee, the inside large nut that was below the Unistrut clamp, loosen and remove from the 1-inch
tee by sliding it over the polycarbonate tube.
Step 7: Holding onto the two 1-inch tee’s, pull the exchanger apart.
NOTE: Under no circumstances, should you pull the exposed portion of the tube specimen through one of the ½” fittings.
This will scrape off all the deposits, and other material from the surface of the specimen, that are on the tube, and you will
not be able to sample it.
Step 8: At this point, the tube specimen may end up being held by either the left or right tee. Grasp the end of the tube
specimen furthest from the 1-inch tee and pull the specimen out of the tee.DO NOT PUSH THE SPECIMEN BACK
THROUGH THE TEE. If the polycarbonate shell is still attached to the 1-inch tee, be careful not to slide the tube specimen
along the inside of the shell wall.
After removing the tube specimens from the exchangers, complete the specimen card which came with the tubes. This
contains the initial weight and the start date for the exposure period if it was filled out correctly. Please fill in the ending
date for the exposure period before submitting the sample to the lab so corrosion rates can be calculated. This is the same
procedure as standard corrosion coupons.
Exchanger Installation:
Once the tubes are removed you just reverse the process to install new tube specimens. Please follow these important
cleaning procedures to ensure the best results.
• Wipe down the tube using an acetone wipe or acetone from the local plant lab. The cleaning of the tube specimen
with acetone is intended to remove any labeling or surface oils used for preservation of the tube.
• A clean green abrasive pad is also recommended to remove oxide layers from the surface of admiralty brass or
copper.
After inserting the new tube specimens into the exchangers be sure you fill out the tube specimen card which came with
the tube and contains the initial weight. This card is required when the tube is removed and sent to the lab for analysis.
You are now ready to start the initial startup process. The o-rings and ferrules can be reused from the inside of the two
compression fittings removed in step 4. Note the positioning of the Teflon ferrule and the two o-rings between the fittings.
After putting the exchanger back together, you must fill the process chamber between the heater and the wall of the tube
specimen.
Open up both fill caps and fill slowly until the process chamber liquid comes out the other side. After inserting the
exchangers in the Sentinel, be sure you fill out the tube specimen card which came with the tube and contains the initial
weight.
NOTE: It is required to use distilled water, treated with nitrite (or similar corrosion inhibitor), to fill the process chamber.
This ensures there is no scale or corrosion on the process side of the exchanger tube and that only events occur on the
cooling water side of the tube specimen. This is the side you are able to observe through the clear polycarbonate outer
tube. Make sure there is at least 1000ppm of nitrite (as NaNO2) in the fluid used to fill the chamber.

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Start Up
Step 1: Install ½” tubes in Sentinel exchangers of the desired metallurgy for the evaluation and ensure the exchangers are
installed in Sentinel.For installation help, please read the section for changing the exchanger tubes.
Step 2: Before continuing, be sure that all breakers in the skid are in the off position.
Step 3: Ensure the supply stream is turned on and make sure both exchanger valves are open. You will visually see both
flow meters for exchangers #1 & #2 moving.
Step 4: We are now ready to turn on the onboard instrumentation.
Step 4a:Make sure the Camera is positioned and pointed parallel to the exchangers. The camera will capture a
picture immediately once fully booted up so you can check the positioning of the camera in Step 4d.
Step 4b: Turn on the breaker labeled “Data/Device”. This will power on the data logger as well as the 2 limit
controllers. The data logger will take 45-60 seconds to fully boot up. At minimum, you must have the included USB Thumb
drive inserted into the data logger. It will not display data without it and is indicated on the screen with “+USB”.
Step 4c: If you have cellular connectivity, you will see “+Internet” displayed on the screen. If the camera is
plugged in, you will see “+Camera” on the screen. The screen will start to display skin temperatures and velocities. You
may see unrealistic values for skin temperature and velocity initially while the readings stabilize.
Step 4d: If you do not have a computer accessible, skip this step. Once fully booted, turn off the “Data/Device”
breaker. Remove the USB Thumb drive and insert it into your own computer. Navigate to the folder labeled “Pictures”
and find the picture associated with the specific date it is. The picture should have a relatively unobstructed view of both
exchangers. Proceed on to the next step. If the camera is pointing in a different direction, return the USB thumb drive to
the data logger, and start the process over with Step 4a.
Step 4e: Return the USB thumb drive to the data logger, turn the “Data/Device” breaker back on, powering back
up the data logger and associated instrumentation. You’re now ready to set the velocity of both exchangers.
NOTE: On the Data Logger display, Exchanger 1 is identified as “T1 or F1”. Exchanger 2 is identified as “T2 or F2” under
“Skin Temps” and “Velocities” respectively.

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Step 5: Set the velocity of both exchangers by adjusting the cooling water. Keep in mind that as you adjust one valve you
will affect the velocity of the other exchanger due to the cooling water coming in via the same inlet header. The displayed
FPS will take a few seconds to stabilize. A second point to keep in mind is that unless you are on a constant pressure-
controlled supply line, your velocity will fluctuate. Once your velocity is set you shouldn’t have to adjust it later in this
process unless you accidently bump a valve in the remainder of the startup process.
Step 6: At this point, you should do a final check before introducing heat into the system.
a) Cooling water is on, not blocked to either exchanger, and set to desired velocity.
b) Each exchanger process chamber is adequately filled with treated water.
c) The rheostats are turned all the way down.
Step 7: Turn on the breakers to the two heaters, and slowly increase the power to each exchanger with the rheostats until
you reach the desired skin temperature.
FINAL NOTES: Setting the velocities and skin temperatures can take some manipulation. Take your time and make small
adjustments to reach your final target velocities and skin temperature. To achieve certain skin temperatures at higher
cooling water velocity, you may have to put the exchangers in series. Please contact Knew Value for skid specific
instructions to put your exchangers in series.

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Ongoing Maintenance & Best Practices
Sentinel does not require much ongoing maintenance once the exposure period has been started. That does not mean that
you should set it and forget it.
As a best practice, we would recommend reviewing the visible results through the clear polycarbonate shell, at a minimum,
once per week. It is also important to check that your velocity and skin temperature settings are still correctly targeted.
External climate and plant operations affect both the supply stream pressure and cooling water inlet temperature.
Exposure period lengths are up to the operator; however, we recommend no more than 90 days per exposure period to
have an ongoing log for continuity. If using traditional corrosion coupons, it is a good practice to coordinate exposure
periods between the Sentinel and the coupons for comparison purposed. Following the completion of an exposure period
the tubes can be replaced and submitted for evaluation. It is worth noting, that the tube specimen and corrosion coupons
will not match.
The following are some tips to consider:
• Check the skid at least once per week for any noticeable leaks and tighten fittings as needed. If water is lost from
the process chamber during a run, turn off the heaters, allow them to cool down by observing the temperature on
the limit controllers. When they are below 100˚F the exchangers are safe to handle.
• Check the operation of the skid at least once per week to ensure correct operation as well as observing cooling
water result.
• If an inlet strainer is installed on the cooling water, check to ensure it is kept clean and cooling water flow through
Sentinel is not lost. Loss of cooling water flow will create non-typical conditions for the cooling water and likely
invalidate the exposure period.
• Please review our limited 1-year warranty. Any failure of components that fall under the warranty in Sentinel
(heaters, flow meter, thermocouples, data logger, circuit breakers or power supply) will be replaced in kind. No
field repair of these components is suggested. Contact Knew Value to be sent replacement parts as soon as
possible.

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Troubleshooting
You must have some amount of mechanical aptitude and common sense to perform troubleshooting work on the skid. It is
also extremely important to note that due to the inevitable variables in operating conditions and the infinite unknowns that
this troubleshooting guide can only cover certain problems. We take great care on the preparation of each unit in hopes
that you do not need to reference this section at all.
Decrease in cooling water velocity:
This can be caused by many issues. Ensure that the supply stream from the plant has not dropped. If the supply stream
does not supply adequate pressure, it is possible to use a booster pump to supplement the pressure to obtain the correct
velocity. If you are using a strainer, make sure this is clean.
Cooling water flow stopped:
Make sure cooling water is still flowing through the supply stream. If cooling water is still flowing to Sentinel, make sure no
one has closed the valves inside the unit to each exchanger. If everything appears as operational, it is possible that the flow
meter has been stopped by debris. You can manually attempt to rotate the debris out of the flow meter. For additional
flow meter operations, please see the support section of our website.
Resetting the limit controllers:
In the event that a heater hits 500˚F the limit controller will cut power to that heater. Before resetting the limit controller,
ensure that you understand why the limit controller went into alarm status. This is likely from a loss of cooling water flow
or the loss of fluid from the process chamber. If these issues have been rectified, you can reset the limit controller by
pushing the “RST” button on the unit showing the alarm status.
We have taken the same approach with all the other components in our skid: replacement, “in kind”, with no repair in the
field. Broken components should be returned to our shop for repair and assessment of any changes for increased
reliability.

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Supplies & Service
Knew Value can provide the following:
- Tube Specimen: Pre-weighed, Passivated or un-passivated. Metallurgy of choice.
- Consumables: Teflon ferrules and “o” rings.
- Exchangers: Spare, pre-assembled exchangers.
- Maintenance
Feel free to contact us directly.
Knew Value, LLC
Huffman, Texas
www.knewvalue.com
[e-mail]
832-603-2039 or 832-233-0481