Rep Login  

How To: Select Nitrogen Cylinders to Pre-Charge a Bladder Tank

How To: Select Nitrogen Cylinders to Pre-Charge a Bladder Tank How To: Select Nitrogen Cylinders to Pre-Charge a Bladder Tank How To: Select Nitrogen Cylinders to Pre-Charge a Bladder Tank How To: Select Nitrogen Cylinders to Pre-Charge a Bladder Tank How To: Select Nitrogen Cylinders to Pre-Charge a Bladder Tank

At times, an expansion tank pre-charge must be increased using compressed air. Wessels recommends dry, oil-free air like the compressed air used in our factory, which is taken to below -50°F and processed through a dryer. Another option is to use compressed nitrogen because it is an inert gas that avoids oxidation and moisture content that can corrode the system. Nitrogen also provides more consistent pressure and is readily available. But how many cylinders are needed to pre-charge a bladder tank to the desired pressure? There are several factors that need to be considered: the size of the compressed gas cylinders, the size of the expansion tank accepting the nitrogen, and the pressure that is needed for the pre-charge.

Additionally, we need to think in terms of stored potential energy. With the product pV (where p is absolute pressure and V is volume) equal to potential energy in joules (ft-lbf), we can calculate the energy in a cylinder of gas and compare it to the potential energy requirement of the bladder tank.

To make the units more conducive to gallons and psia, let’s use pV in terms of GAP (gallons times absolute pressure in psia). Gas cylinders are rated in cubic feet. This is actually the cubic feet of gas at 150 psig (164.7 psia) that, when released, would make up that amount of volume in cubic feet at 0 psia. In terms of potential energy in terms of GAP, the amount of energy in each cylinder is equal to 100 times the “rated” cubic feet of the cylinder. A 20 cubic foot cylinder charged to 2,200 psig yields a potential energy of 20 x 100 = 2,000 GAP.

Some common size cylinders whereas the rating in Cubic Feet based on 150 psig:

Be aware that the rating for the cylinders is referenced above 0 psia. If charging a tank to a pressure greater than 0 psia, which of course is any expansion tank, the potential energy will be somewhat less, but this will yield a close approximation.
For example, if the tank at the job site is 250 gallons and needs to be charged from 40 psig to 90 psig, this requires the potential energy to be increased:

250 gallons × (90-40) psia=12,500 GAP

Bottle “H” is rated for 244 Cu.Ft. or 24,400 GAP above 0 psig. To recalculate the potential energy above 90 psig, a simple ratio should be used:

The 14.7 factor to convert psig to psia drops out of the equation and yields:

For the above example, the resulting cylinder potential energy above the 90-psig set point for the expansion tank calculates thusly:


The potential energy above 90 psig for the “J” 330 cu.ft. is 23,402 GAP and is large enough to handle the tank in this example. An alternative is to take two (2) “Q” tanks which also have the necessary GAP requirement for the example expansion tank.

An excel spreadsheet is available to download for evaluating most potential jobs.

Written by:
Sam Fuller
Technical Sales Engineer
Wessels Company

Full width regal divider
September Employee Spotlight

September Employee Spotlight

Megan McDaniel is one of the smiling faces in Wessels Company’s filtration department.  Megan has been with Wessels for about 9 years and has been our filtration purchasing manager for 4 years. She attended University of Southern Indiana and she has two children, both of whom have red hair and blue eyes.  When she’s not in the office, she enjoys watching movies, listening to music and competing at trivia night.  An interesting fact about Megan is that she writes, eats, and brushes her teeth left handed, but plays all sports with her right hand.  During football season, she roots for the Indianapolis Colts and the Chicago Bears.

Megan’s fast facts:

Favorite Color: Purple
Favorite Food: Mexican
Hobbies: Playing outside with her kids and trivia night
Nickname: Megmo Jackson

Megan McDaniel
Filtration Purchasing Manager
e-mail: [email protected]
phone: 317-888-9800 ext. 1031
cell: 317-443-4154

How To: Acceptance Volume vs. Tank Volume

How To: Acceptance Volume vs. Tank Volume

Tank Volume: The overall volume of the tank, including air and water.

Acceptance Volume: The amount of water inside the tank.

Maximum Acceptance Volume: The maximum amount of fluid inside the tank before stretching the bladder/diaphragm.

Acceptance Factor: The percentage of of tank volume storing fluid, expressed as a decimal.

Drawdown Volume: The amount of water that is drawn out from a starting tank pressure down to the minimum pressure.

A tank’s drawdown volume is the amount of water that is stored between a high and low pressure, which is usually determined by a pump switch.  In real-world plumbing systems, the tank should not start at the maximum pressure and the air cushion pressure should not fall to zero.

The volume of water in a tank, called the acceptance volume, is sometimes expressed as a decimal or percentage against overall tank volume, called an acceptance factor. However, the tank should be charged on the tank’s air side to the minimum pressure needed within the system and filled to the maximum pressure in water required to adjust the tank’s pressure correctly. (pressure in the tank should be set accordingly: 10% below pump cut-in pressure (hydropneumatics); equal to pressure reducing valve pressure (hydronic), equal to line pressure (thermal – domestic water heater protection). As a standard, Wessels Company offers tanks pre-charged to 40 PSI, which can easily be adjusted and reduced in the field to fit the pressure needed within the system.

All replaceable bladder tanks Wessels offers are considered a full volume acceptance tanks, since the bladder inside can fully expand within the tank, allowing all the available space inside the tank to be used.  Fixed-diaphragm tanks are not full acceptance tanks because the diaphragm is confined to only a portion of the tank.

You can tell if a tank is a full acceptance tank by looking at its chart either online, on the submittal, or in the literature for each style of tank.  If the chart says tank volume, that means the usable volume inside the tank is the total volume of the tank.  For example, in a Wessels Company NLA series tank, the total volume of the tank is also the number of gallons the tank can hold, making the tank a full acceptance volume tank. A fixed-diaphragm tank like the NTA, however, lists both the tank volume and the maximum acceptance volume.

If you have more questions about tank volume and Wessels products, feel free to reach out by chatting with us in the chat window at the bottom right of our website, by emailing us at [email protected], or by calling our offices at 317-888-9800.

August Employee Spotlight!

August Employee Spotlight!

Guy Kirk has been part of the Wessels Company family for over 20 years!  He is the Vice President and East Coast Sales Manager.  He enjoys playing and watching all sports, particularly sailing and he loves eating seafood. In his spare time, he enjoys rooting for his favorite teams: New England Patriots, Boston Red Sox and the Indianapolis Pacers.

 

Guy fast facts:                                                                              
Favorite color:  Green

Favorite food: Steak and seafood

Likes: sports, sailing

Hobbies: rooting for and watching sports

How To: Understanding the Makeup of Glycol Makeup Packages

How To: Understanding the Makeup of Glycol Makeup Packages

How To: Understanding the Makeup of Glycol Makeup Packages

Wessels Company makes Glycol Makeup Packages in Glymatic, Single, Double, and Twin systems. The purpose of a GMP is to maintain system pressure.

In the sequence of operation in a system using a GMP, the glycol solution mixture is held in a solution container and then is pulled through a pump. The pump has an internal spring that utilizes a pressure relief valve, if the pressure in the system is too high. Fluid goes into the pump, the pressure is increased with a rotary vane, and then is discharged into the system at a higher pressure.

The package is protected by a low water cutoff probe in the solution container. Two probes are in the container and monitor the glycol mixture

level. If the level falls too low, the continuity between the offset probe is broken and the pump is shut off, which sounds an alarm.

The pump is controlled by a pressure switch, which is set to turn on at 60 psi and to cut off at 80 psi. The 80 psi of fluid is then stored in an expansion tank to hold the excess fluid. The expansion tank is a diaphragm tank that has a pre-charged pressurized air cushion, which helps maintain the pressure in the system to 80 psi.

The fluid then flows through a pressure reducing valve or PRV, which is set for the system’s required pressure. The valve’s range can go from 10 to 70 psi, which can be for whatever pressure your system needs.

Inside the PRV, a spring sets the tension that holds the valve open. The valve can be set to point downstream between 10 and 70 psi, the spring will hold the valve open until the downstream pressure equalizes the spring tension through the diaphragm, that will hold the diaphragm up and close the valve.

Wessels Company offers four different types of GMP systems: a glymatic, a single, duplex, and twin. A Glymatic system package is a free-standing solution reservoir that holds the glycol/water solution at atmospheric pressure. A pressure assembly is mounted on the solution reservoir’s cover keeping the pressurization unit off the floor. This GMP uses a pressure station to move fluid from a 6 or 15-gallon reservoir pressurized to between 1 and 25 psi, up to 130° F. The solution then remains stored until it is needed to replenish the system that has lost its glycol/water or water solution.

The single system GMP automatically services one closed-loop system. This GMP holds a reservoir of 50 or 100-gallons and 1/3 and 1/2 horse power pump pressurization control station with magnetic starter. The 1/3 HP is used for systems of 50 PSI pressure and the ½ HP station is used for systems up to 70 PSI.

The Duplex system or GMPD, services two separate closed-loop systems. This system is available with 50- or 100-gallon reservoir and 1/3 or ½ HP pump pressurization control also with magnetic starter.

The Twin system or GMPT also services one closed-loop system and is available with the 50 or 100-gallon reservoir with 1/3 or ½ HP pump.

However, a control panel with alternator and dual magnetic starter is used with this system to easily and automatically alternate between two pumps.

To see exactly how the GMP system works, you can watch our technical video, here.

You can also learn more about the GMPs, on our website, here.

Upgrades Coming to Fixed-Diaphragm Tanks

Upgrades Coming to Fixed-Diaphragm Tanks

Wessels Company is proud to announce the popular WessView Bladder Integrity Monitor and integrated pressure gauge are coming to the NTA, TTA, and FXT lines of fixed-diaphragm tanks.

By mid-September, Wessels will roll out these much-requested upgrades as standard features for our fixed-diaphragm HVAC expansion tanks, domestic hot water tanks, and well water and pressure booster tanks.

The WessView is an innovative bladder integrity monitor that alerts you to moisture outside the fixed-diaphragm inside the tank. In addition, a handy pressure gauge provides a quick and easy way to check the pressure of the air cushion surrounding the diaphragm.

These upgrades have been standard on Wessels Company’s on removable bladder tanks for over a year now and the reviews are in: our customers love it!

The new submittals are available on our website now: NTA, TTA, FXT

Updates to other literature are in development. Download the new NTA Brochure below.

 

NTA Brochure

 

How To: Retrofit Your Tank with WessGuard

How To: Retrofit Your Tank with WessGuard

Wessels Company’s patented WessGuard® system is the industry’s first sentry for critical mechanical system protection. Mechanical systems are expensive to install and potentially more costly to service or replace. WessGuard® acts to protect the critical components of the mechanical system by monitoring the effectiveness of the system expansion tank. WessGuard® can be installed in new installations or retrofit to many of the vessels installed today.

Wessels WessGuard® system can be retrofitted to nearly any removeable bladder-style expansion tank. The system monitors the fluid within expansion tanks by determining excessive movement of the vessel bladder. It incorporates a capacitive proximity sensor that determines if fluid levels in the expansion tank exceed “normal” operating conditions. If a tank bladder is compromised, the WessGuard® monitors the rising fluid level in the tank. The monitor alerts users of the potentially unsafe conditions by activating an audible alarm and includes a set of dry contacts to tie directly to an energy management system.

How would a retrofitted WessGuard® benefit your tank and overall system? If a tank in the system has a compromised bladder and the user is not sure why, a WessGuard® may help determine the cause. It also provides maintenance an added level of protection by serving as an early warning system.

If you suspect your tank has a compromised bladder and a pressure test has revealed no issues, the WessGuard® will be able to help the user to determine if a power surge is causing the system to receive no power or if the bladder is overfilling.

For maintenance or for replacing a bladder, be sure to check the inside of the tank to make sure there aren’t any rusted sharp points that may cause a bladder to be punctured.

Any tank that has been manufactured by Wessels, whether it is 12 years old, or 12 minutes after it’s been shipped to its destination, can be retrofitted to add a WessGuard®. However, if the tank is more than 18 months old, the WessGuard® will have to be custom made.

In newer model tanks, made since the beginning of 2018, a WessGuard® can simply be added to the prefab bracket on the side of the tank and screwed into the pre-existing spud where the WessView® is currently located.

The update itself takes about 5 minutes to complete. However, the tank will have to be taken off-line, decompressed, and then recompressed after the WessGuard® is added to the outside of the tank and then returned to the system. This sensor is shielded and has a metal casing around it that helps to protect the face of the sensor.

With the new style WessGuard®, in the new style tanks, every tank and sensor are set up and installed the same way. But with the previous-style tanks and the original WessGuard® design, every tank that receives a retrofit must be done to fit each specific tank. In order to install a WessGuard® in a previous-tank, our quality control supervisor will measure the length of the cord needed for the sensor to hang internally and monitor the volume of the tank.

With the previous-style tanks, there is a one-inch spud at the top of the NLA and FXA 1000 and above. The WessGuard® monitor goes in and will be dropped down until it gets to about 60% of the tank volume. This sensor is not shielded, but it does have bumper rings around it to keep it from getting a false positive.

The cord for the newly installed WessGuard® on a previous-style tank is surrounded by a pressure fitting, so the tighter the fitting is installed, the better the pressure is held inside the tank. The one-inch stainless steel fitting has a gasket inside of it, which the cord for the sensor is threaded through and a nut on the inside. Once the nut is tightened, the gasket and cord are tightened and help the pressure stay inside the tank.

When retrofitting a WessGuard® to a newer style tank, the sensor replaces the WessView®. However, in the older style tanks, because the WessView® was formerly optional, the WessGuard® goes in from the top and not a pre-existing plug. Because with the older style tank, there is no pre-fab box to attach the WessGuard® to, it comes with an epoxy which is used to attach the WessGuard® box on the outside of the tank.

Using air that is too moist to fill the tank could potentially affect the monitor and may give a false positive. It is important to make sure when filling the tank, the air being used must not be too wet.

Retrofitting or purchasing a WessGuard® for your system is always a good idea and adds an extra layer of protection to your tank, bladder and overall system. The WessGuard® can give your maintenance a little piece of mind, knowing an issue with the bladder will be signaled sooner than later.

If you would like to purchase a WessGuard® with your next tank order, or if you would like to have a WessGuard® retrofitted to a previous-style tank, you can visit our website at westank.com or you can call our office to inquire about retrofitting an older style tank.

July Employee Spotlight

July Employee Spotlight

Chanel Warner is an administrative assistant and front-desk receptionist at Wessels Company’s headquarters and is coming up on her 1 year anniversary in the position. Chanel enjoys styling hair in her spare time. She also enjoys dogs and shopping, but dislikes cats and toxic behavior.

Chanel’s fast facts:

Favorite Color: Purple
Likes: Dogs, Shopping
Dislikes: Cats, Toxic People
Hobbies: Hair Styling and Fashionable Clothes
Nickname: Nelly

Chanel Warner
Administrative Assistant
e-mail: [email protected]
phone: 317-888-9800

June Employee Spotlight

June Employee Spotlight

Frank Rios is regional sales manager and a technical support agent who has worked with Wessels for over 9 years. Frank’s career began in the Navy and he later attended Ivy Tech to pursue a career in Business Management. He enjoys running, playing golf, basketball, and target shooting. When he’s not at work, he enjoys rooting for the Boston Celtics and the Denver Broncos. Frank is also very passionate about his family, friends, and work ethic.

Frank’s fast facts:

Favorite Color: Green
Favorite food: Steak
Likes: Traveling, basketball, golf, and target shooting
Dislikes: Liver, so don’t even ask!
Fun fact: Learned English age 12

Frank Rios
Regional Sales Mgr. / Support
e-mail: [email protected]
phone: 317-888-9800
cell: 317-696-1487