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Sprayer Pump Types, Costs, and Specifications

Sprayer Pump TypesThere are six (6) common sprayer pump types used across applications: centrifugal, diaphragm, roller, transfer, piston, and irrigation injection. Selecting the sprayer pump or pumps right for the job requires an understanding of the various styles, operation and installation specifications, and correct use to maximize the pump's performance.

The different sprayer pump types have been engineered to provide a full range of operation pressures and max GPM flow rates, size dimensions, material compatibility, and power source options so select pumps will be most suitable for certain applications. There are seven (7) power source options for sprayer pumps: gas, electric, hydraulic, belt/pulley, PTO, pneumatic, and pedestal.

Sprayer pumps are most commonly used for pumping water and/or chemicals. Pump pricing is dependent on its intended use due to work needs and ranges from $80 up to $3,000.

Guide Contents:

  1. Operation performance and application information for the different sprayer pump types
  2. Multiple approaches to selecting the most job-suitable pump
  3. A step by step calculation guide to determining job and system required pump capacity (GPM)

Selecting a Sprayer Pump

Determine: (a) the pump’s overall intended use, (b) specific job operation needs, (c) the compatibility of the pump casing and gasket materials with the spray fluid and/or any additional chemicals, fertilizers, powders, granules, etc., and (d) the pump’s required performance specifications based on the spray system needs and the pump characteristics of size, orientation, installation, power source, and its total plumbing GPM* and PSI pressure.

Based on the pump use, sprayer system requirements and operation specs, select the pump and design that will satisfy your specific job requirements. Example: selection of a PTO driven, 1" NPT Silvercast 5-roller pump, 45 GPM max flow rate, and 200 max PSI for use in farm herbicide applications by tractor mount.

*A step-by-step guide is provided to help calculate the job's required pump GPM. This section is best suited for agricultural field sprayers, booms, and boomless nozzles.

Sprayer Pump Basics

Sprayer pumps are mechanical devices designed to generate a pressure differential to drive spray fluid from a storage tank, through system plumbing, and out to the spray nozzle(s).

Sprayer pumps are classified and selected for use according to their:

  • 1. Pump Engineering Method of Driving Fluid
  • 2. Power Source TypePump's Mechanical Input
  • 3. Fluid Flow Rate Gallon Pump Capacity
  • 4. Pump Housing Material Pump Casting
  • 5. Gasket Material System O-Ring Seals

 

Applications and Uses

Sprayer pumps and their systems are used across various industries within applications for agriculture, commercial business, professional landscaping, manufacturing, and the maintenance of land, foliage, or pests.Sprayer Pump Examples Common scenarios and uses involving sprayer pumps:

  • Booms and boomless sprayers
  • Agricultural field sprayers
  • Row crop sprayers
  • Irrigation for fields, farmland, vineyards, nurseries, greenhouses
  • Sprinkler systems
  • Delivery of crop performance-chemicals
  • Chemical transfer
  • Potable water, fresh water, and salt water transfer and dewatering
  • High pressure / focused target spot spraying
  • Soil, pasture, lawn, foliage herbicide / weed killer application
  • Roadway maintenance
  • Foliage control
  • Insect / pest protection and elimination
  • Manufacturing product line sprayers
  • Sewage and trash
  • Fluid circulation
  • Pressure washing

Operation Characteristics for Pump Selection

There are six (6) primary pump characteristics used to determine a specific pump for an operation. These are the pump’s use, dimensions and size, power source, GPM flow rate, pressure delivery capabilities, and shaft rotation. It is important to select the pump that will fully integrate into your sprayer system.

Sprayer Pump Selection Based On:

Use Pump total performance should suit the needs of the job application; Examples: Piston pumps for high-pressure, high-distance nozzle water delivery; irrigation injection pumps for metered delivery of multiple crop-performance chemicals simultaneously; PTO-driven centrifugal pumps for high-volume fluid transfer via tractor mount, nurse tank fill; etc.
Size Dimensions Industry standard pumps are manufactured in various size dimensions to ensure pumps will fit both the equipment and the system.
Power Source Seven power drive options are available to match a spray system’s engineered method for power delivery; i.e. gas, electric, hydraulic, PTO, belt, pneumatic, pedestal.
GPM Flow Rate GPM flow rate is directly related to power source strength and inlet/outlet sizing. The correct pump is also recommended to have a 20% greater GPM than the job's base duty requirements to account for system distance-pressure loss, additional attachment pressure use, and potential flow inhibition associated with chemical characteristics or plumbing restraints.
Pressure System fluid pressure is directly related to pump capacity and inlet/outlet sizing. The right sprayer pump will supply a nozzle(s) with the PSI wanted or required to deliver the spray fluid where it’s needed and how it’s needed.
Rotation Pump drive shafts have either clockwise (CW) or counterclockwise (CCW) rotation. Direct couple mounting pumps must have a rotation opposite of the coupling shaft. For reference: gas and electric motor engine shafts have CCW rotation: use CW pumps; tractor PTOs have CW rotation: use CCW pumps.

Types of Sprayer Pumps

Centrifugal Pumps

Centrifugal sprayer pumps use the rapid circular motion of an impeller to pull spray fluid contents through system plumbing. Centrifugal pumps are non-positive displacement pumps with perhaps the broadest selection of available engineered options due to their compatibility with the spray fluids and chemicals of many applications. Internal pump hardware is generally manufactured from durable, resistant materials such as stainless steel.

Centrifugal PumpThese pump types are generally self-priming and capable of low flow and high flow output from 25 GPM up to 1400 GPM. Centrifugal pumps have nozzle delivery pressures that cap around 150 PSI during low flow operations. They come in various power sources with many effective options, and are available in:

Pump Material: Cast Iron; 316 Stainless Steel; Polyethylene; Polypropylene; E-Coated Cast Iron;

Power Source/Drive: Gasoline; Hydraulic; PTO; Belt/Pulley; Electric;

Standard Gasket Material: Viton; EPDM; Silicon Carbide; Buna-N;

Centrifugal pumps are simply designed, durable, and versatile. They make excellent choices for semi-abrasive spraying commodities and wettable powders due to the additional mixing performed by the pump. Centrifugal pumps are excellent pumps for low pressure, high flow rate applications. Stainless steel models are approved for potable water operations. The flow control systems of centrifugal pumps are very simple and easy to control, which contributes to the pump's common use for pesticide applications.

For more information on pump characteristics and performance data: Shurflo Centrifugal Pumps, Banjo Centrifugal Pumps, and Ace Centrifugal Pumps.

Diaphragm Pumps

Diaphragm sprayer pumps are engineered to separate the pump's sensitive mechanical parts from potentially corrosive or abrasive pump solutions, and are often selected for use due to this pump characteristic. Diaphragm pumps have all moving parts isolated and suspended in oil to make them very durable, long service pumps.
Diaphragm Pump
In this pump type, the synthetic diaphragm generates a positive pressure gradient that drives fluid flow to the system nozzle(s). This pump model is self-priming and capable of low to high pressures up to 725 PSI. Diaphragm pumps have relatively low flow capacity, from 0.6 GPM to 68.7 GPM, and are available in:

Pump Material: Aluminum; Aluminum Poly Hybrid; Polyethylene; Polypropylene;

Power Source/Drive: Gasoline; Hydraulic; PTO; Belt/Pulley; Air (Pneumatic); Electric;

Standard Gasket Material: Viton; EPDM; Desmopan; Buna-N;

Diaphragm pumps are used in the wide application of crop protection chemicals; i.e. pesticides, fungicides, and herbicides. Additional common applications include various jobs for agriculture, pest control, and garden or nursery operations. Diaphragm pumps make excellent choices when needing higher nozzle pressure delivery and/or when needing separation of the spray fluid from the pump mechanical components due to potential corrosion or abrasion damage.

For more information on pump characteristic and performance data: Low Pressure Diaphragm Pumps, Medium Pressure Diaphragm Pumps, and High Pressure Diaphragm Pumps.

Roller Pumps

Roller pumps are commonly utilized and well known for their versatility and simplicity in use, maintenance, and engineering. This pump type has internal rollers that revolve to create a positive pressure differential that generates fluid flow. The rollers, 4-8 in quantity, are made of specific materials for compatibility, common types include: Teflon®, nylon, rubber, or polyethylene.

Roller PumpsRoller sprayer pumps have flow rate capacity ranges from 9.1 GPM to 62 GPM and can generate nozzle delivery pressures up to 300 PSI. They are self-priming and are available in:

Pump Material: Cast Iron; Ni-Resist; Silvercast;

Power Source/Drive: Gasoline; Hydraulic; PTO; Belt/Pulley; Electric;

Standard Gasket Material: Viton; Buna-N;

Roller pumps make both work-and-cost effective choices for operations that use small to medium sprayer systems or multi repeated systems due to regional topography, crop plots, or other reasons. Highly utilized and economical, roller pumps are mechanically simplistic and very effective, compact sprayer pumps.

For more roller pump information, see the following characteristics and performance data.

Transfer Pumps

Transfer PumpTransfer pumps feature large diameter inlets and outlets as well as increased GPM power sources for high volume transfer of fluids, semi-solids, or other suspended solutions as in trash, waste operations. Transfer pumps are designed for high rate capacity jobs of bulk fluid exchange. Some transfer pump models feature steel caging for easy vehicle transport.

This pump type has flow rate capacities ranging from 40 GPM to 484 GPM, with nozzle delivery pressures ranging to 100 PSI. Transfer pumps are generally self-priming and well suited for bulk movement operations. Available in:

Pump Material: Cast Iron; Aluminum; Polypropylene;

Power Source/Drive: Gasoline; Hydraulic; Electric; Pedestal;

Standard Gasket Material: Viton; EPDM; Buna-N;

Transfer pumps are an effective pump option for moving a lot of material efficiently. Common use applications are in water transfer, de-watering needs, and for chemical solutions as in bulk storage transfer and nurse tank crop-chemical filling. Polypropylene and cast iron transfer pumps are recommended for chemical uses and aluminum is recommended for water.

For more information, see the following transfer pump characteristics and performance data.

Piston Pumps

Piston pumps feature a piston cup pumping mechanism that force-compresses spray fluid through supply lines and out to the system nozzle(s). The fluid contact head of the piston pump often features a chemically resistant sealing material (e.g. Buna-N rubber (nitrile), polyethylene) that is replaceable on wear for pump maintenance and service life.

Piston PumpPiston pumps generally require priming. They provide consistent nozzle delivery pressures that can range up to 120 PSI with capacity flow rates from 10.2 GPM to 68.4 GPM, and are available in:

Pump Material: Cast Iron;

Power Source/Drive: Gasoline; Hydraulic; Electric; PTO;

Standard Gasket Material: Viton; Buna-N;

Piston pumps see heavy use in large-distance crop watering applications potentially including fertilizers and crop protection chemicals. They are also commonly used in cleaning, pressure washing type applications. Dual piston pump models are also available that allow the dual administration of spray fluid products.

For more information, see the following piston pump characteristics and performance data.

Irrigation Injection Pumps

Irrigation Injection PumpsIrrigation injection, also called fertigation, pumps are piston style sprayer pumps that feature a variable stroke piston and micro-meter flow control module for easy rate adjustment and controlled chemical metering of irrigation systems and crop-performance chemicals. Components exposed to spray solutions are either polypropylene or 316 stainless steel for compatibility. Single phase or three phase injection pump styles are available with the potential to deliver up to three different chemicals, each at their own rates, simultaneously.

Fertigation pumps offer extremely accurate flow rates for water and chemical delivery. Nozzle delivery is consistent and features micrometer adjustment. Injection pumps are generally self-priming with standard operating pressures from 120 to 150 PSI. GPM flow rate capacities range from 0.5 GPM to 7.8 GPM. They are available in:

Pump Material: Cast Iron; Polypropylene; 316 Stainless Steel;

Power Source/Drive: Gasoline; Belt/Pulley; Electric;

Standard Gasket Material: Viton; Buna-N;

Metered injection pumps have been engineered to be easily incorporated and expanded into sprayer systems. They are well corrosion-resistant and specialized for highly-controlled spray fluid delivery. These pumps are recommended for liquid use only, solutions containing granular or semi-solid materials are not recommended.

For more information, see the following for Full Meter Injection Pumps and E-Z Meter Injection Pumps

Sprayer Pump Power Source Options, Benefits, and Uses

Sprayer pumps can be selected according to the system's power design or scenario requirements, sometimes meaning multiple option choices. Some pump power source models may be limited in their pump characteristics and capability ranges. Match full pump specifications to the power source and system performance needs. A sprayer pump will be powered according to one of the following source methods:

Pump Power Sources and Use Details

Gasoline Powerful, independent pump choice capable of service when and where power sources may be limited or nonexistent; Ideal for high pressure use as well as high volume fluid delivery.
Electric Instant actuation pumps without refuel requirements; Ideal for extended use operations and when pump air intake quality, contamination may be a concern; Common use in industrial / agricultural mixing, blending, and transferring; Available in 12V, 115V, 230V.
Hydraulic Pump choice for integration into a hydraulic drive system mount; Mounting location can vary; Not tied to PTO, drive shafts, or belts; Strong pump types, simplified maintenance, repair, and replacement.
Belt / Pulley Installs and integrates into many engine-driven pumping systems; Common and versatile pump drive method; Belts are easy to replace with minimal downtime and overhead; Well suited for manual or self-designed pumping systems.
PTO Driven Mounts directly to 540 RPM and 1000 RPM PTO shafts; Common for tractor installation use in agriculture, chemical administration, and pest/foliage maintenance control; Easy operation, installation, and maintenance repair.
Pneumatic Convenience of operated by air-pressure systems; Self-priming, fast actuation, steady pressure flow; Ideal for tough pump jobs involving transfer, injection, and spraying of chemicals, fertilizers, and other ag-crop products.
Pedestal Transfer pump power source option; Pedestal-mounts are often centrifugal pumps made of thick cast-iron or polypropylene; Ideal for liquid fertilizer applications.

Sprayer Pump Compatible Power Source Options

To determine a specific pump's available / compatible power sources, use the following chart that summarizes the different pump models and matching power drive options.

Pump Engineering and Power Type Compatibility Chart

Centrifugal Diaphragm Transfer Roller Piston
PTO 540 RPM

Direct Couple

Gear Drive

Belt/Pulley

PTO 1000 RPM

Direct Couple

Gear Drive

Belt/Pulley

Gas Engine

Direct Couple

Gear Reduction

Belt/Pulley

Electric Motor

Direct Couple

Belt/Pulley

Hydraulic Motor n/a
12 Volt DC Motor n/a

Sprayer Pump Operational Specifications

The following sprayer pump performance characteristic table summarizes the available pump model max flow rates, nozzle delivery pressures, and pump operation speeds.

Sprayer Pump Operation Characteristics

Pump Type Displacement Max Flow Capacities Pressure Range Operation Speeds
Centrifugal Non-Positive 25 – 1,400 GPM 5 – 150 PSI 2,000 – 4,500 RPM
Diaphragm Semi-Positive < 1 – 68 GPM 50 – 725 PSI 200 – 1,200 RPM
Roller Positive 5 – 62 GPM 50 – 300 PSI 800 – 2,600 RPM
Transfer Non-Positive 40 – 484 GPM 28 – 100 PSI 2,000 – 4,500 RPM
Piston Positive 7 – 68 GPM 120 – 1,015 PSI 450 – 550 RPM
Irrigation-Injection Positive 0.5 – 7.8 GPM 120 – 150 PSI Metered / Variable Stroke

Sprayer Pump Flow Rate Ranges

When selecting sprayer pumps by flow capacity, recommendations are to select pumps with a GPM 20% greater than the minimum application flow rate. This extra rate serves to guarantee maximum system operation by accounting for additional pressure needs with system plumbing, components, any additional attachments, as well as fluid characteristics. This recommendation is made for all sprayer systems when selecting and implementing a pump by GPM.

Pumps can be organized and selected according to their GPM pump capacity. Different applications may require the use of select GPM pumps. Pumps can be classified as Low, Medium, or High capacity pumps with operation ranges from 0.6 GPM up to 1400 GPM, depending on pump type. Sprayer pumps according to flow rate capacity:

  • Low Capacity: > 50 GPM
  • Medium Capacity: 50 – 200 GPM
  • High Capacity: > 200 GPM

Sprayer Pump Casting Materials

Sprayer pumps' house castings are available manufactured from different types and combinations of metal and plastic. The best pump material for a select system may depend on conditions such as pump-to-chemical compatibility, weather sensitivity (e.g. exposure to extreme heat, cold, dust, precipitation), or hygiene standard requirements. The correct pump material will match its intended use and factors such as long-term resistance, pump service, system longevity, and cost.

Refined metals, plastic pumps, and coated iron overall experience excellent chemical resistance, increased pump longevity, and are often well suited for agricultural crop-performance applications.

Common sprayer pump manufacture materials arranged by availability and frequency of use:

  • • Cast Iron
  • • Polyethylene
  • • Polypropylene
  • • 304 Stainless Steel
  • • Aluminum
  • • E-coated Cast Iron
  • • Silvercast
  • • Ni-Resist
  • • 316 Stainless Steel
  • • Aluminum Polyethylene Hybrid

Sprayer Pump Gasket Materials

Sprayer pump gasket seals can vary in their manufacture material and chemical durability. Selecting the correct gasket is important in ensuring consistent system performance and pump service life. Different gasket materials can be resistant to different spray solutions. Verifying gasket and fluid compatibility is always a recommended step. For more information concerning compatibility of common ag chemicals and pump component materials.

Common sprayer pump gaskets arranged by material and use frequency:

  • • Viton
  • • EPDM
  • • Buna-N
  • • Desmopan
  • • Silicon Carbide

How Specific Gravity and Plumbing Restrictions Affect Pump GPM

The reported sprayer pump capacity (GPM) value is calculated by the pump manufacturer during minimal plumbing restrictions with water as the test fluid. The pump GPM value is established according to water’s specific gravity rating (SG: 1.00) and it's weight (8.34 lbs/gal). Whenever considering a sprayer pump, know pump GPM ratings are calculated based on pumping pure, warm water. Any change in pump fluid characteristics will either increase or decrease the actual experienced pump GPM.

The GPM rate of increase / decrease varies with the spray fluid’s specific gravity vs water’s specific gravity:

When pumping fluids more dense than water, actual pump GPM will decrease

When pumping fluids less dense than water, actual pump GPM will increase

Calculating for Adjusted Pump GPM

To compensate for fluids with specific gravity's different from water and to calculate an adjusted sprayer pump GPM, determine:

1. Specific gravity of the spray fluid to be pumped

• To calculate the specific gravity of the spray fluid if unknown: Spray Fluid Weight (lbs/gal) ÷ Weight of Water (8.34 lbs/gal) = Spray Fluid Specific Gravity; Example: What is the specific gravity of Atrazine weighing 9.89 lbs/gal? Atrazine Weight 9.89 lbs/gal ÷ Water Weight 8.34 lbs/gal = 1.19 Atrazine’s Specific Gravity

2. Material-specific conversion factor

• Material specific conversion factors are based on an average between the spray fluid’s SG and water’s SG; see the following:

Spray Fluid, Weight Specific Gravity Conversion Factor

6.00 lbs/gal

0.72 SG

0.86

7.50 lbs/gal

0.89 SG

0.94

Water: 8.34 lbs/gal

1.00 SG

n/a

11.5 lbs/gal

1.38 SG

1.19

15.3 lbs/gal

1.83 SG

1.42

 

• To calculate the material-specific conversion factor: ( SG Water + SG Spray Fluid ) ÷ 2

3. Adjusted pump flow capacity GPM

• To calculate adjusted pump GPM: Original Pump GPM × Material-Specific Conversion Factor = Adjusted Pump GPM Flow; Example: Original Pump 115 GPM x 1.095 Atrazine Conversion Factor = 126 GPM Adjusted Pump Capacity

• The total job-required pump GPM may actually be higher when considering an adjusted pump flow along with system plumbing, attachments, and potential fluid flow restrictions.

Plumbing Restrictions

In addition to specific gravity, the experienced pump GPM can be diminished due to restrictions experienced within the plumbing and piping systems attached to the pump. To achieve optimal pump GPM in a sprayer pump, route the liquid flow from pump to nozzle with minimized restrictions and pressure draw. Minimizing line restrictions allows a pump to perform nearest to its rated max flow capacity. Sprayer pump system pressure loss may be associated with:

  1. Incorporating line system plumbing that has various size diameters;
  2. Using system hose sizes that are different from pump inlet / outlet ports;
  3. Overuse of plumbing elbows, valves, and fittings;
  4. Pressure gauges or valves installed on pump suction side rather than discharge side, and;
  5. Not having straight, pump suction plumbing 10 times longer than the its inner diameter measurement.

How to Calculate Job-Required Sprayer Pump GPM

A series of mathematical operations can be used to approximate a spray job’s required pump flow capacity. To calculate the required sprayer pump flow rate in gallons per minute (GPM), we will determine: (1) Total Distributed Fluid; (2) Boom/Sprayer Nozzle GPM; (3) Boom/Sprayer Flow GPM; (4) Tank Agitation Rate, and; (5) The Required Pump Capacity.

Step 1  |  Sprayer Application Information

Multiply: Application Rate, in Gallons per Acre (GPA1) x Average Speed (MPH) x Spacing2 (inches) = Total Distributed Fluid (TDF)

Step 2 | Calculate Nozzle GPM (if not already known)

Divide: TDF from Step One ÷ 5940 = Gallons per Minute (GPM) per Nozzle

Step 3 | Calculate Total System Nozzle(s) Flow

Multiply: GPM per Nozzle x System’s Number of Nozzles = System Flow in GPM

Step 4 | Calculate Tank Agitation Flow Rate

Multiply: Typical agitation rate3 is 5% to 10% of total tank volume: Tank capacity volume (gallons) x 5% - 10% = Agitation Rate in GPM

Step 5 | Calculate Total Required Pump Flow

Multiply: System Flow x Agitation Rate = Required Total Pump Flow in GPM

1. GPA = (5940 x Nozzle GPM) ÷ (MPH x *Spacing)
2. Spacing = Nozzle spacing (inches) between nozzles for booms and other multi-nozzle operations; or the spray width (inches) of a single nozzle or boomless nozzle
3. The agitation flow rate calculated is not applicable for jet agitator systems, nor systems without agitators. Calculating for jet agitation is a ratio of the system’s input gallons to output gallons.

• Example: 1 input gallon provides 4 gallons output agitation. Given the calculated needed pump capacity is 85 GPM; the corrected pump capacity needed is: 85 GPM x ¼ (1 gal. input / 4 gal. output) = 21.25 GPM

Selecting Your Sprayer Pump Takeaways

A sprayer pump's overall fluid drive influence will diminish with distance from the pump and when the fluid passes through individual system components, such as tank agitators, strainers, elbows, valves, etc. Pump performance can be affected by the spray fluid's characteristics as well as temperature, and varies by sprayer pump engineering and power drive. To fully satisfy job duty requirements and deliver the desired nozzle pressure and GPM, select a material-compatible pump with the operation specs and power source sufficient for the entire system, any restrictions, and the spray fluid's characteristics.

Here at Sprayer Supplies, we believe in integrity, hard work, and professional, quality equipment that meets or exceeds the needs of the application. Our team aims hard when it comes to helping professional businesses, farms, and individuals in selecting the sprayer pump that is right for the job and right for their system. For any questions concerning sprayers, pumps, or equipment, contact us.