the basics

Waterra Pumps are available in four (4) performance ranges: Standard Flow, High Flow, Low Flow and Micro Flow.

features

• self tapping male or female threads for quick installation
  
• ball contained in valve for quick sealing and fast valve reaction
  
• valves fit our custom valve wrench for ensuring secure attachment
  
• constructed from organic resistant materials
  
• inexpensive and reliable
  
• suitable for well development, purging, sampling and VOC sampling

using the performance chart

The Performance Chart shown below is an example of how Waterra has classified the performance capabilities of its four Inertial Pump Systems. This chart is intended to assist you with the selection of the most suitable system for your specific site. Please note that the ratings have been calculated by actual field testing in a variety of well conditions and therefore may seem somewhat conservative in value.

Sample Chart

Depicts full range of flow from the maximum possible to the lowest sustainable flow. Typical flow rates usually fall between the two values. Expect the best flow rates in high yield (minimum draw down) wells with large water columns.

our most popular system

The Standard Flow System is the most popular inertial pump. This system is best suited for 2" monitoring wells and can provide lifts of 150 to 200 feet. Flow rates can be as much as 1 gallon per minute.

The system consists of two components – a Standard Flow foot valve and a length of 5/8" OD Standard Flow high density polyethylene (HDPE) tubing.

The most commonly used foot valve is the 1 inch OD, acetal thermoplastic D-25. Optional foot valves include the stainless steel 3/4" OD SS-19 and the 5/8" OD D-16 and SS-16.

The Standard Flow System is best used in wells off 1” to 2” inside diameter. This system is suitable for a variety of sampling environments. Optional tubing includes low density polyethylene (LDPE) (Canada only) and Teflon (FEP).

The Standard Flow System is frequently used because if offers the ability to develop new monitoring well installations and can remove even the most turbid groundwater with no detrimental effect to the pump. Once development is completed the same pump can be used to both purge and sample the well. Since the system is so affordable most customers choose to dedicate the inertial pump to the monitoring well thereby eliminating the
need for decontamination.

recommended devices

The Standard Flow System can be manually operated in most wells simply by holding the tubing by hand and oscillating it up and down in the well. Sometimes performance and endurance can be improved with the addition of the Waterra Lever Pump (WLP 100).

The greatest performance improvements are realized with the use of the Waterra Hydrolift-2, Waterra PowerLift-3, PowerPack-PP1 or PowerPump-2. The use of one of these automated actuators greatly improves the well development capacity of the inertial pump. The automated actuators are also recommended when substantial purge volumes are required.

well development

The inertial pump has a substantial capacity for developing monitoring wells because of the cyclical action of the valve in the well screen area. This characteristic can be utilized to remove silt and sediment that has accumulated in the foot of the monitoring well and can also be used to remove fines from the sand pack and well screen.

The well development capacity of the Standard Flow D-25 foot valve can be enhanced by installing a SBD-25 Surge Block to the D-25 foot valve. The surge block effectively increases the outside diameter of the D-25 foot valve to 1 7/8”, reducing the annular gap between the valve and the inside of the well screen. This results in a significant increase in the surging action of the valve. The use of the inertial pump and surge block together is one of the most effective methods for developing monitoring wells because it simultaneously surges and pumps
the well. This frees up silt and sediment in the sand pack and screen, breaking down bridging, drawing these particles it into the well and then removing them from the well.

STANDARD FLOW Performance Chart

The Performance Chart shown above displays the performance capabilities of the Standard Flow System. This chart is intended to assist you with the selection of the most suitable system for your specific site. Please note that the ratings have been calculated by actual field testing in a variety of well conditions and therefore may seem somewhat conservative in value.

The performance (flow rate) of the inertial pump is affected by a number of parameters. The inertial pump works by imparting upward momentum to the water column within the pump's tubing. Momentum is imparted to the water column in the pump's tubing at the end of the upward pump stroke. If sufficient momentum has been imparted to this water column, then more water is drawn into the tubing through the foot valve. This occurs during the downward stroke.

Factors that effect flow rate include such parameters as the depth of submergence of the foot valve, tubing diameter, well casing diameter, the length of pump stroke and the speed of oscillation of the pump.

Obviously, the speed of oscillation is the primary factor in imparting momentum to the water column in the pump's tubing. Generally a pumping rate of 100 to 180 strokes per minute is recommended. The recommended stroke length is 4 to 6 inches, with a longer stroke performing better in deeper piezometers.

Greater submergence of the foot valve increases the pressure differential (the pressure difference between the water within the tubing and the head pressure outside the valve) that is created at the end of the upward pump stroke. Increasing the pressure differential increases the rate of water inflow through the valve at the end of the upward stroke, thereby increasing the flow rate.

Another factor affecting the flow rate with the inertial pump is size of the annular gap between the inertial pump tubing and the ID of the well casing. When the inertial pump is operating, the flexible tubing will tend to wobble from side to side within the well casing. This wobble results in some of the up and down movement applied at surface to the tubing not reaching the depth where the valve is located. For this reason, the stiffer High Density Polyethylene tubing is usually preferred in deeper monitoring wells (depth in excess of 60 – 70 feet). The inertial
pump performs best in smaller diameter piezometers (4” or less).

deep well sampling

The High Flow System is designed to be used in 2 inch wells or larger where a high pumping rate is desired or where very deep wells are encountered. This system is also an excellent well development tool in 2 inch piezometers.

Consisting of a High Flow valve, either the 1.25" OD, acetal plastic D-32 or the stainless steel SS-32 and a length of 1" OD high density polyethylene (HDPE) tubing, the High Flow system can provide lift of up to 250-300 feet in 2 inch monitoring wells and flow rates of up to 4 gallons per minute.

recommended devices

The High Flow System is considerably heavier than the Standard Flow system and consequently is not nearly as suitable for manual operation. The High Flow System can be manually operated in monitoring wells up to a maximum depth of about 60 feet depending on the operators strength and endurance.

It is recommended to use an automated actuator with the High Flow System. The Hydrolift-2, PowerLift-3, PowerPack-PP1 or PowerPump-2 are all recommended for use with the High Flow System. The PowerPump-2 is the most powerful actuator produced by Waterra and will operate this system to it's maximum limits.

well development

The inertial pump has a substantial capacity for developing monitoring wells because of the cyclical action of the valve in the well screen area. This characteristic can be utilized to remove silt and sediment that has accumulated in the foot of the monitoring well and can also be used to remove fines from the sand pack and well screen.

The well development capacity of the High Flow D-32 foot valve can be enhanced by installing a SBD-25 Surge Block to the D-32 foot valve. The surge block effectively increases the outside diameter of the D-32 foot valve to 1 7/8” reducing the annular gap between the valve and the inside of the well screen. This results in a significant increase in the surging action of the valve. The use of the inertial pump and surge block together is one of the most effective methods for developing monitoring wells because it simultaneously surges and pumps the well. This frees up silt and sediment in the sand pack and screen, breaking down bridging, drawing these particles it into the well and then removing them from the well.

The development capacity of the High Flow System is greater than that of the Standard Flow System because the pump generates a higher flow rate and the larger diameter tubing is stiffer and flexes less in 2” monitoring wells.

Waterra can also produce on a special order basis larger surge blocks for use with the High Flow D-32 foot valve for use in monitoring wells with diameters larger than 2”.

HIGH FLOW Performance Chart

The Performance Chart shown above displays the performance capabilities of the High Flow System. This chart is intended to assist you with the selection of the most suitable system for your specific site. Please note that the ratings have been calculated by actual field testing in a variety of well conditions and therefore may seem somewhat conservative in value.

The performance (flow rate) of the inertial pump is affected by a number or parameters. The inertial pump works by imparting upward momentum to the water column within the pumps tubing. Momentum is imparted to the water column in the pumps tubing at the end of the upward pump stroke. If sufficient momentum has been imparted to this water column, then more water is drawn into the tubing through the foot valve, this occurs during the downward stroke.

Factors that affect flow rate include such parameters as the depth of submergence of the foot valve, tubing diameter, well casing diameter, the length of pump stroke and the speed of oscillation of the pump.

Obviously, the speed of oscillation is the primary factor in imparting momentum to the water column in the pumps tubing. Generally a pumping rate of 100 to 180 strokes per minute is recommended. The recommended stroke length is 4 to 6 inches with a longer stroke performing better in deeper piezometers.

Greater submergence of the foot valve increases the pressure differential, (the pressure difference between the water within the tubing and the head pressure outside the valve) that is created at the end of the upward pump stroke. Increasing the pressure differential increase the rate of water inflow through the valve at the end of the upward stroke thereby increasing the flow rate.

Another factor affecting the flow rate with the inertial pump is the size of the annular gap between the inertial pump tubing and the ID of the well casing. When the inertial pump is operating the flexible tubing will tend to wobble from side to side within the well casing. This wobble results in some of the up and down movement applied at surface to the tubing not reaching the depth where the valve is located. For this reason the stiffer High Density Polyethylene tubing is usually preferred in deeper monitoring wells (depth in excess of 60 – 70 feet). The inertial pump performs best in smaller diameter piezometers ( 4” or less).

As a general guide, in most 2” monitoring wells, the High Flow System D-32 will usually produce a flow rate of about 1 to 3 gallon per minute given 20 to 30 feet of valve submergence. The High Flow System has a substantial lift capacity in 2” diameter piezometers. Some customers have reported lifts approaching 300 feet.

piezometer sampling

The Low Flow System is designed to be used in small diameter piezometers (usually 1.5" ID to 0.75" ID). It can provide flow rates of up to 1/2 gallon per minute and can lift water from up to 100 feet.

This system consists of a low flow valve, either the acetal plastic D-13 foot valve or the stainless steel SS-13 foot valve and HDPE, LDPE or FEP (Teflon) tubing.

The Low Flow System D-13 and SS-13 valves have a male thread which allows them to have a maximum outside diameter of 5/8” (13mm). This narrow diameter means that they will often fit into piezometers that can not be accessed by the Standard Flow System.

In some deep well situations it may be necessary to secure the Low Flow foot valve to the tubing with a small screw. In deeper wells the hydraulic pressure applied against the tubing where the valve can be substantial. This pressure pushes against the walls of the tubing and against the valve and may ultimately pop the valve out of the end of the tubing. The use of HDPE tubing is preferred in these situations because it is stiffer than the LDPE tubing and will expand less under high pressure. Additionally, the valve can also be securely fastened to the tubing by driving a small sharp stainless steel screw through the tubing wall, penetrating the threaded portion of the foot valve. The stainless steel SS-13 valve has a small ho;e in the threaded portion of the valve which will accept screws used for this purpose.

recommended devices

The Low Flow System is probably most frequently operated by hand, although the Waterra Hydrolift-2 and the Waterra Lever Pump (WLP 100) can also be used to operate this system.

damaged wells

The Low Flow System is also useful for sampling in damaged or obstructed monitoring wells. This system is also useful for sampling in small diameter monitoring wells with low head levels or poor recharge. The smaller diameter tubing used in the Low Flow System and lower flow rate produced by this system means that the pump itself contains a smaller volume of water when full, leaving more water in the piezometer available for pumping and ultimately sampling. A pump with a larger storage volume or higher flow rate could potentially purge the well dry or displace the all of the standing water in the well into the pumps tubing and still not have delivered any all of the way to the surface.

LOW FLOW Performance Chart

The Performance Chart shown above displays the performance capabilities of the Low Flow System. This chart is intended to assist you with the selection of the most suitable system for your specific site.

Please note that the ratings have been calculated by actual field testing in a variety of well conditions and therefore may seem somewhat conservative in value.

micro well usage

The Micro Flow System is popular for use in direct push technology micro well installations and multi-level installations. The SS-10 foot valve can deliver a sample from as deep as 75 feet and flow rates with this system are usually less than 1/2 gallon per minute.

This system consists of a small (3/8" OD) stainless steel SS-10 foot valve and a length of either HDPE or FEP (Teflon) tubing.

recommended devices

The Micro Flow System is usually hand operated.

damaged wells

The Micro Flow System is also useful for sampling in damaged or obstructed monitoring wells. The maximum outside diameter of the Micro Flow System is 3/8” (10mm). This small maximum diameter allows this pump to fit into many tight situations that outer devices can't get near.

MICRO FLOW Performance Chart

The Performance Chart shown above displays the performance capabilities of the Micro Flow System. This chart is intended to assist you with the selection of the most suitable system for your specific site.

Please note that the ratings have been calculated by actual field testing in a variety of well conditions and therefore may seem somewhat conservative in value.

well development

The Waterra Surge Block is an excellent well development tool. It simply press fits over the body of the Standard Flow or High Flow foot valve (D-25 or D-32). The inertial pump has a substantial capacity for developing monitoring wells because of the cyclical action of the valve in the well screen area. This characteristic can be utilized to remove silt and sediment that has accumulated in the foot of the monitoring well and can also be used to remove fines from the sand pack and well screen.

The surge block effectively increases the outside diameter of the D-25 or D-32 foot valve to 1 7/8” In 2” wells and 3 7/8” OD in 4” wells, reducing the annular gap between the valve and the inside of the well screen to approximately 1/16” . This results in a significant increase in the surging action of the valve.

The use of the inertial pump and surge block together is one of the most effective methods for developing monitoring wells because it simultaneously surges and pumps the well. This frees up silt and sediment in the sand pack and screen and breaks down bridging, drawing these particles it into the well and then removes this material from the well.

The recommended method for developing a monitoring well with the inertial pump and surge block is to begin the development process with the surge block near the top of the well screen. Operate the pump with the surge block in this position until the turbidity level of the water beiing delivered from the pump decreases to an acceptable level. Once this level is reached then the surge block is lowered in the well screen one to two feet and the process is repeated. Developing wells in this manner is one of the best methods, often resulting in turbidity levels below 10 NTUs.

features

• surge blocks are available for the D-25 and D-32 foot valves
• designed for use in 2” or 4” schedule 40 monitoring wells
• Waterra can also produce special order surge blocks for unique well diameters