Selective catalytic reduction is an advanced process that is intended to minimize pollution from diesel engines and contribute to better air quality. Diesel exhaust fluid, or DEF, is central to this process.
If you use modern farm or construction equipment you are well aware of the regulations that require the use of DEF. Although DEF is a simple liquid, consisting of urea and water, it does have unique properties. So for those who need to fuel equipment, the question arises what kind of pump do I need for DEF?
In this guide, Will will be looking at the properties of DEF to understand what types of materials are compatible with it. We will also take a look at the different DEF pump options and accessories.
Understanding What Pump Types Are Suitable for DEF
The most important thing to consider when selecting a pump for DEF is material compatibility. There are other factors to consider such as flow rate and drive type, but this is most important. Let’s look at the materials that work for pumping DEF and the types of pumps that will work.
Material Compatibility
Diesel Exhaust Fluid (DEF) is a solution made up of 32.5% urea and 67.5% deionized water. DEF is non-toxic, non-flammable, and non-hazardous under normal conditions. However, DEF is not compatible with most metals and some plastics. This limits the pumps that are suitable to be used with it.
How important is this really? What is the worst that can happen if you use just any old pump? Simply put, it may work for a very short period but it won’t be long before you have issues. DEF decomposes into ammonia, which corrodes incompatible metals like copper, zinc, and aluminum. It causes pitting, erosion, oxidation, and galvanic corrosion, weakening metal and leading to rapid component damage.
So what materials do work with DEF? Stainless steel (grades 304 and 316), polyethylene, and polypropylene are resistant to the effects of DEF. Therefore manufacturers use these materials to construct pumps suitable for DEF. The seals and gaskets used for DEF pumps are EPDM or Viton.
Material suitable for handling DEF:
- Polypropylene
- Viton
- EPDM
- Stainless Steel
Pump Types for DEF
Although the materials suited for DEF are limited, there are several different types of pump that will work fine for DEF fluid. Centrifugal pumps, diaphragm pumps, gear pumps, and even submersible pumps. Again, the type is not as important as the materials and elastomers used to construct the pump.
Centrifugal pumps are most common for large volumes, and diaphragm pumps are used for dispensing into vehicles and equipment. Diaphragm pumps for DEF will generally come as a kit that includes the hoses, nozzles, and couplings needed for DEF barrels or other pre-packaged containers (more about this in a moment).
- Centrifugal Pumps
- Diaphragm Pumps
- Submersible Pump
Pump Drive Types for DEF
A variety of drive options can be used for DEF Pumps. Electric motors, gas engines, hydraulic motors, air-driven pumps, and more. No matter what kind of power supply, you can find a pump that will work for you.
- Electric
- Gas-engine Driven
- Air Operated
DEF Pump Couplings
Many DEF tanks and containers utilize Micromatic RSV valves and couplings. These couplings are designed to prevent contamination of DEF. They have a dry-break mechanism that minimizes the exposure of DEF to the environment during connection and disconnection, maintaining the purity of the fluid
These couplings also help to eliminate drips or spills. Even a small amount of DEF fluid can corrode metals, so the dry-break feature is vital to protect any equipment around your DEF pump and tank.
RSV Coupler |
RSV Drum/Tank Valve |
RSV couplings are the same type of couplings used on beer kegs and other chemical containers. There is a valve in the tank or drum, and there is the coupler on your pump or suction hose.
There are two different types of Micromatic couplers: 3-key and 4-key. The reason for this difference is to prevent cross-contamination of equipment. For example, it prevents you from coupling a DEF pump to a tank containing some other chemical.
How to Connect the Micro Matic RSV Dispense Coupler
DEF Pump Options
Due to the specific applications and the limited materials that are compatible with it, manufacturers have designed pumps and pump units specifically for DEF. There are 12-volt options available for mobile applications as well as stainless steel centrifugal pumps for bulk transfer.
12-Volt DEF Pumps
- Flowserve: CT6-DEF
- Fill-rite: FRDF012-PO
- Piusi: PJ33102
- MP: MX35322
- Dura: DP6518-AE12
115-Volt DEF Pumps
- Piusi: PJ33101
- Flowserve: CT6-DEFA
- Fill-Rite: FRDF120-PO
- Dura: 6518-AE110
Air Operated DEF Pumps
- Filrite: FRAP32V
DEF Pump Kits
Understanding that DEF is only compatible with certain materials, you must be careful when selecting a pump, but then you have to piece together a hose, nozzle, meter, and tank that is compatible. This is time-consuming and nerve-racking if you are not certain that an item will work with DEF.
DEF pump manufacturers understand this and offer comprehensive solutions. There are several DEF pump kits that include a pump, hose, RSV coupler, and all the other appropriate fittings needed. These kits are often designed to hang off an IBC tote or 275-gallon shuttle. Some of these kits will even include a tank.
DEF Pump Kits for Cage Tanks/IBC Totes
12-Volt Kits:
- Dura: DP6518-AE12
- Fill-Rite: FRDF012
- Piusi: PUF101A1A
- Flowserve: SICT6-DEFD
110-Volt Kits:
- Dura: DP6518-AE110
- Piusi: PUF101AOH
- Fill-Rite: FRDF120
- Flowserve: SICT6-DEFE
DEF Pump Kits with Tank
58 Gallon Tank Kit: PUPPT58
116 Gallon Tank Kit: PUPPT116
135 Gallon Tank Kit: DP2512-AE-135
DEF Pumping Accessories
Your pump’s compatibility with DEF is vital, as are the accessories you use to handle it. Here are some essential accessories to consider and the types that work with DEF:
DEF Tanks
Polyethylene and stainless steel are the best materials for DEF storage. Poly is much more affordable. You can use just about any poly tank but you will want to ensure that the tank is properly sealed up and equipped with dry-break couplers to preserve the purity of your DEF.
As mentioned earlier RSV couplers are the common method to ensure closed system transfer. These can be added to a tank if you do not have them. The RSV tank valves are made to fit into different thread types. If you use a 275-gallon IBC tote/Cage tank, you can replace the lid with one that will fit an RSV coupler.
DEF Tank Options:
DEF Hose
EPDM rubber is the preferred hose to use for DEF. Hose fittings should be either polypropylene or stainless steel. There are also poly and stainless hose reels designed to handle DEF.
Other DEF Accessories:
Let Us Know if You Need Help
DEF is a uniquid fluid with properties that dictate that you use the right type of pump and accessories to handle it safely. Fortunately, the pumps that work with DEF are clearly designed to do so. If you have questions about whether or not a specific product will work for DEF let us know.
Tech Ag & Industrial Sales
Shane Blomendahl is a tech sales veteran at Dultmeier Sales with over 10+ years of experience in liquid handling products covering several industries and applications.