F.A.P. Plus™ ZW System

The TRUE zero-water, product-only recovery system

Groundwater remediation pump with "Zero Water" pneumatic logic and AccuPos™ indicator.

Remediation Applications

  • LNAPL and DNAPL recovery.
  • Recovery of a wide range of products from light-end hydrocarbons with SSU values of 80 or lower, such as gasoline, diesel fuel, hydraulic fluids, to more viscous products like #6 heating oils. For recovering products with higher viscosities, the F.A.P. Plus™ may be used with our high-viscosity rod skimmers or our density skimmers.
  • 2" or larger wells.


The F.A.P. Plus™ ZW groundwater remediation pump (TR-51640) consists of a flexible, special inner bladder and a flexible Buna-N® hose which forms the outer pump body. The pump operates by alternately inflating and deflating the annular space between the inner bladder and the outer hose. When compressed air is applied, the inner bladder collapses. When the air is exhausted, the inner bladder rebounds to its original shape thereby causing a suction which pulls fluid into the pump and up to the surface. The pump is capable of producing a suction of 17 inches of mercury for the recovery of viscous product and operation in deep wells up to 200 feet.

F.A.P. Plus™ ZW is an upgraded version of the basic F.A.P. Plus™ pump. The ZW model incorporates the “Zero Water” pneumatic logic that stops and starts the F.A.P. Plus™ ZW automatically — depending on the position of the skimmer inlet — and prevents the ingress of water when the water level rises more than the skimmer travel allows. The AccuPos™ Indicator helps locate the product/water interface level accurately which makes it easy to install the pump at the correct depth.


The F.A.P. Plus™ ZW remediation pump system comprises seven main components:

F.A.P. Plus™ ZW pump

Skimmer Assembly

The standard skimmer is used to recover gasoline, jet fuel and most diesel fuels. It combines a TR-57-17 Skimmerdensity float, a special hydrophobic element, a product bypass, a hollow guide rod and a coiled hose. The center guide rod allows the skimmer to travel freely in response to the water table changes. The skimmer is designed to float with the inlet positioned at the water/product interface automatically providing 36” of skimmer travel. The density float is used to position the special hydrophobic element — the skimmer inlet — at the product water interface. The hydrophobic element uses a special micron pore size that is based on surface tension, allowing only product to pass. A larger pore size is available for use with higher viscosity products such as weathered diesel. Pumping rates through the hydrophobic element will be approximately 100 gallons per day. Tech Tip: The larger micron-sized elements may allow a small percentage of water to pass. The bypass element is attached to the top of the hydrophobic element and allows the product to enter the skimmer directly when the product layer is greater than 2 inches. Recovery rates through the bypass element are approximately 300 gallons per day. The complete skimmer element is connected to the bottom of the guide rod by a coiled polyurethane hose. This coiled hose can accommodate water level changes of up to 36 in automatically maintaining the skimmer intake at the water/product interface. A minimum distance of 24 in from the bottom of the well to the water/product interface is required when using the TR-517. The TR-51711 requires a minimum of 18 in and provides 24 in of travel. The skimmer can also be configured as a passive device by attaching a quick connect canister on the bottom of the skimmer, providing greater flexibility for free product recovery projects. See Passive Skimmer. Maintenance: Biofouling may occur because the hydrophobic element is positioned at the air/product interface. If fouling occurs, the element can be cleaned using a soft brush or replaced by unthreading the bypass element and installing a new hydrophobic element.
Model Description
F.A.P. Plus Skimmer, 36" travel (min. 24" travel required)
TR-51718 F.A.P. Plus Skimmer, 18" travel (min. 18" travel required)
TR-51711 F.A.P. Plus Skimmer, 24" travel (min. 18" travel required)
High-Viscosity Skimmers

High-Viscosity Skimmers

This skimmer is used when the product has a viscosity higher than 80 SSU, such as oils. The 4 in high viscosity skimmer uses the same design as the TR-517, less the hydrophobic and bypass elements. The skimmer has a 30 in travel and a specific gravity of 0.95, allowing it to float at the water/ product interface. The product collects on the top of the skimmer inlet and, from there, is pumped to the surface. In normal applications the skimmer will remove product down to a ¼ in to ½ in product layer. The skimmer can be adjusted in the field to remove the product even further and attain a thinner layer.
Model Description
4" High Viscosity Rod Skimmer (30" travel)
FAP Density Skimmers

FAP Density Skimmers

Density skimmers are used when there is less than 18 inches of fluid from the bottom of the well to the water/product interface. These skimmers have a specific gravity of 0.95 and float in the water with the top inlet just above the product/water interface. The skimmers have an effective travel of 24 inches. The 2 in and 4 in sizes are for use in well casings with these nominal inside diameters. The 6 in and 12 in models are self-supporting and may be used in large diameter wells, open excavations and open water applications.
Model Description
TR-702 2'' Density Skimmer (1.65" dia.)
TR-704 4'' Density Skimmer (3.5" dia.)
TR-706 6'' Density Skimmer (5.5" dia.)
TR-712 12" Density Skimmer (11.5" dia.)

Important elements in choosing a F.A.P. Plus ZW™ system are:

  • Water table fluctuations
  • Product viscosity
  • Type of product
  • Well diameter
  • Amount of product present
  • Depth from bottom of well to product/water interface

Well Clincher

Well Clincher

Well Clincher

The Well Clincher or cap has expandable, pass through fittings for the air supply tube and product discharge hose, allowing the pump depth to be easily adjusted. The Well Clincher fits over and seals the casing to prevent foreign materials entering the well. Standard sizes available for 2 in to 8 in well casings, custom sizes available upon request.
Model Description
TR-762 2'' Well Clincher for F.A.P. Plus
TR-764 4'' Well Clincher for F.A.P. Plus
TR-766 6'' Well Clincher for F.A.P. Plus
TR-768 8'' Well Clincher for F.A.P. Plus

Pneumatic Overfill Protection Device

Tank-Full Shut-Off (Pneumatic) Tank-Full Shut-Off (Pneumatic)

Shuts off fluid supply to remediation tanks when full.


This pneumatic device is activated by a high liquid level in the recovery tank. Once activated, it shuts the air supply to the pneumatic pump, stopping fluid discharge to the tank.
Enclosure PVC and 6061 aluminum
Chemical Compatibility, Exterior Components Refined petroleum products
Compressed Gas Supply 0 to 100 psi, filtered to 40 microns (see note 1)
Compressed Gas Consumption 0 scfm
Control Valve 2 way, normally open, 20 scfm @ 100 psi (see note 2)
Operating Temperature 33 to 120°F. (see note 3)
Compressed Gas Connections Primary ¼” O.D. push-to-connect tubing fittings.  Secondary ¼” female NPT on bulk heads
Operation Status Indicator Pressure indicator colorimetric, “Green” compressed gas is supplied to pumps, “Black” compressed gas is shut off to pump(s)
Reset After Shut Down Manually operated
Note 1: The use of synthetic oil in an air compressor can cause chemical deterioration of components In the Control Valve that could result in failure of the unit.
Note 2: The TR- 75713 can support up to six FAP+ZW skimmer pumps. Consult with a factory representative before using a larger number.
Note 3: If the unit must be operated in temperatures less than 33°F., then a desiccant air dryer must be used to reduce the dew point of the moisture in the compressed gas to a lower temperature than ambient. If using inert compressed gas, check with the supplier concerning the dew point temperature of the inert gas supplier.
Model Description
TR-75713 Tank-Full Shut-Off (pneumatic)

Filter/Regulator Assembly

Filter Regulator AssemblyThe 5-micron coalescing and auto-drain device is used to filter compressed air to operate the pump. An element indicator provides a visual indication when the filter elements need to be serviced. The regulator allows the pump operating pressure to be set according to the depth of the pump.

Model Description
TR-748 Filter-regulator

Electric Air Compressor

Air Compressor

Air Compressor

An electric, non-explosion-proof 2.5 hp, indoor-use air compressor producing 4.2 scfm is supplied with the standard F.A.P. Plus™ Pump System (TR-515). 1150 or 230 V. 20-gal, ASME code steel tank. This compressor can be used with up to three F.A.P. Plus™ systems. A 5-hp compressor is available for use with more than three systems.  
Refer to air flow and pressure loss table Water Flow and Pressure Loss table  


The standard hose size from the outlet side of the filter regulator to the F.A.P. Plus™ pump is a ¼” Push-Lok™ fitting and a 3/8" barb fitting on the air inlet side. The standard F.A.P. Plus™ fluid discharge line has a 3/8" barb fitting. The hose sizes may have to be increased depending on the distance between the system components.
Hose selection table
Water Flow and Pressure Loss table

Field Applications Photo Gallery & Installation Description