In the Midwest many facilities rely on glycol as a heat transfer fluid that also provides freeze protection. Ordering and receiving a glycol delivery should be a fairly straightforward and easy process; however, it takes some insight and planning to avoid complications.
A story about a contractor who made the wrong call when ordering glycol.
We recently had a contractor place a bulk delivery order for glycol. They followed protocol and completed the necessary paperwork but failed to specify and plan for what was really needed for their system. Here is an illustration of what can happen without proper planning.
A bulk delivery order was placed for X gallons of 35% glycol and a delivery date was selected. The day before the delivery they were not ready to receive the shipment and called to reschedule. This resulted in heavy fees to return the unused product since it was already set for delivery. The product was rescheduled, but when it arrived they were short on volume and the 35% glycol that was ordered was a different concentration than the 45% glycol that was already in the system. A second order was rushed to the site, that resulted in an additional delay. A week later another drum was ordered to completely fill the system. After the system was ready to be tested the contractor asked if the product was formulated for aluminum boilers. Aluminum components were not noted on the order so the product did not have the correct inhibitor package. Special accommodations needed to be made to lower the pH and offset this error. In the end, an order that should have taken a few days took over a month to fulfill.
To accurately order glycol you need to fully understand the application of equipment, the freeze point required and system design to properly specify the correct type and formulation.
There are two standard types of glycol that are commonly used in industrial applications, ethylene and propylene.
- Provides better heat transfer and is less viscous
- Is more compatible with certain systems
- Used for most industrial applications
- Much more toxic than propylene
- Less toxic, more environmentally friendly, and more likely to meet discharge regulations
- Food grade and Kosher formulas are available.
- Used in applications where the user may come in contact with the fluid or will be discharging to the sewer
Things to Consider When Selecting Glycol
Type: Specify the correct type, ethylene or propylene, for your application
Inhibitor Package: You can order glycol with or without inhibitors. A variety of inhibitor packages can be formulated depending on your application.
Note: If your system has aluminum components you must specify this when ordering so your supplier can formulate the correct inhibitor package to protect your system.
- New system: Refer to the manufacturers recommendations.
- Old system: You need to know the formulation and type of glycol that is currently in the system. You can’t mix ethylene and propylene and you should make sure the % concentration is correct in the existing system. Be prepared to balance it out if not.
Concentration Percentage and Freeze Point: Glycol can be ordered in concentrations from 20-100%. The percentage of concentration is determined by the freeze point you require. As a general rule it is good to order 25% glycol or higher because it offers a natural biological inhibitor.
The chart below is a guide for ordering propylene. So, for example, if you require freeze protection to -30°F you would order propylene at 50% concentration.
|Typical Concentrations of DOWFROST Fluid Required to
Provide Freeze and Burst Protection at Various Temperatures
|| Percent DOWFROST Fluid Concentration Required
| For Freeze Protection
| For Burst Protection
| -7 (20)
| -23 (-10)
| Source: Dow Chemical
Note: These figures are examples only and may not be appropriate to your situation. Generally, for an extended margin of protection, you should select a temperature in this table that is at least 3°C (5°F) lower than the expected lowest ambient temperature. Inhibitor levels should be adjusted for solutions of less than 30% glycol. Contact Dow for information on specific cases or further assistance.
Attention: These are typical numbers only and are not to be regarded as specifications. As use conditions are not within its control, Dow does not guarantee results from use of the information or products herein; and gives no warranty, express or implied.
Volume: It is important to specify the proper quantity and to plan for how to handle any overage amounts when ordering large volumes. Things to consider:
- Are you filling the system all at once or in stages?
- Do you want it delivered in drums, totes or in a tanker?
- < 500 gallons - you will most likely want drums or totes
- 500+ gallons you may want to consider a tanker. Bulk deliveries can be a little more complex and there are some things to consider, such as:
Timing: Must be able to coordinate that it arrives within hours of when you need to fill the system.
Access: Must consider truck access to fill location and the distance from truck to the connection point.
Pressure: Pressure required to fill the system may be affected by building height or system volume. Most tankers can only deliver up to 40 psi.
Volume: You need to calculate so that you get the correct amount. It is a good idea to order a few empty totes to store any excess glycol. It costs more to send back any overage amounts.
Watertech’s Bulk Delivery Form can help avoid any mishaps when ordering large volumes.
Test The system
Once the system has been filled use a refractometer to check the system or have someone test that it is within the parameters specified.
Having the correct information at hand when placing an order will help ensure you get exactly what you need and save time and frustration of having to adjust your order. If you have questions on specifying glycol, please reach out to your Watertech representative for help.
||Jeff Freitag – Director of Sales, Watertech of America, Inc.
Jeff has been in the water treatment industry for almost 30 years and has a diverse background in water chemistry, pretreatment equipment, filtration, chemical feed and control, testing and monitoring, training, and consulting. He joined the Watertech team in 2000 and has held several positions before moving into his current role as Director of Sales. Some who know him call him “Jeff.” Most who have worked with him call him “The Water Guy.”