Call: 704-786-1700

neptune logo

Neptune Chemical Pump Company manufactures chemical metering pumps including hydraulic diaphragm metering pump,electronic diaphragm metering pump, fertilizer pump, chemigation pump and accessories.

Series 500 “Dia-Pump

Metering Pumps – Series 500 “dia-Pump”

Neptune Hydraulically Actuated “dia-Pumps”

Variable Oil By-pass™ stroke adjustment allows better valve performance than variable linkage designs. The valve checks have extra time to seat even in heavy liquids since they are idle during the by-pass portion of the suction and discharge strokes.

Neptune Hydaulically actuated dia pumps EZE-CLEAN™ Valves–Cartridges can be removed for cleaning without disturbing the piping to the pump.

All Neptune “dia-Pumps” are adjustable from 10% through 100% of capacity by micrometer dial.

Neptune “dia-Pumps” are available in the following materials of construction:
• Cast Iron with 316SS Trim
• 316SS • PVC • Alloy 20 • Kynar

 500aStandard “dia-Pump” Simplex Only

  • Simplex capacities from 1 gph (3.7 lph) to 18 gph (68 lph)
  • Pressures to 1100 psi (77 kg/cm2)
 500eEconomy Liquid Head Simplex Only

  • Simplex capacities from 1 gph (3.7 lph) to 18 gph (68 lph)
  • Pressures to 1100 psi (77 kg/cm2)
 500s 5000The Original “dia-Pump” Available Simplex or Duplex

  • Simplex capacities from 0.2 gph (0.75 lph) to 80 gph (302 lph)
  • Pressures to 3000 psi (210 kg/cm2)

Electronic Stroke Control

Metering Pumps – Electronic Stroke Control

electronic stroke controlPurpose

The Neptune Electric Stroke Control allows the capacity of any Neptune Series 500 or Series 600 “dia-PUMP” to be automatically controlled in response to a standard 4-20 mA process signal. Also accepts 0-5 VDC/0-10 VDC signal or digital pulse train inputs. One-piece controller- positioner mounts directly to the pump. No machining or any special drillings or tappings needed to retrofit pump. Ideal for water/wastewater, power and process industry applications…anywhere that pump flow must be automatically proportioned or varied.


  • Stroke position indicator on controller. (Also on optional remote control module.)
  • Permits fast, easy visual check of pump stroke length.
  • Remote control unit (optional). Allows manual override and monitoring from remote location.
  • Switch reversible. Allows direct or indirect response to signal.
  • Separate signal and power entrance connections to terminal blocks.
  • Adjustable ratio. Great control flexibility.
  • Signal interruption “memory.” If process signal is lost, unit can remain in its last position or move to a preset position.
  • Adjustable travel time: 15 seconds minimum
  • Input signal optically isolated from the line voltage. Eliminates inexact positioning which could be caused by extraneous electrical interference.
  • Alarm function relay monitors: 1) movement to max/min preset limits; 2) movement to adjustable upper/lower limits. Gives early warning to malfunctions or process upsets, allows for quick corrective actions.

Low Volume Pumps

Metering Pumps – Low Volume Pumps

low volume pumps

Special Application Pump

Neptune Model 5003/5005 hydraulic diaphragm metering pumps are built to deliver very low flows, repeatable and accurate ranging down to quarts per day. Discharge pressures are higher than are possible with mechanical diaphragm pumps. Explosion-proof models are available for use in hazardous atmospheres.

These pumps are especially popular in oil/gas production, oil recovery and refineries. Typical applications include the injection of antifoam agents, corrosion inhibitors and other additives injected at very low volumes but high pressures. (Refer to curves on reverse side.) These pumps are also used for neat feeding of boiler chemicals.

Design Features/Benefits

  • High discharge pressures, to 3000 psi (210 kg/cm2) Exceeds limits of most small pumps, ideal for high pressure systems
  • EZE-CLEAN™ valves — Cartridges can be removed for cleaning without disturbing piping
  • Electric stroke-length control available — automatic capacity control in response to standard 4-20 mA process signal (variable speed drives may not be used with Models 481 or 501 due to low stroking speed)
  • Explosion-proof motors available — suitable for use in hazardous atmospheres
  • Low flow-rates–quarts/day — accurate, reliable chemical feed

E Series “Dia-Pump”

Metering Pumps – E Series “dia-Pump”

e series dia pump

Economy Diaphragm Pump
Series 500-E offers an economical alternate to the standard Series 500 “dia-PUMP” or an opportunity to “step-up” from packed plunger pumps to a true hydraulic diaphragm pump at a modest cost increment.


  • Capacity to 18 gph (68 lph); Pressure to 1100 psi (77 kg/cm2)
  • Available liquid end materials: 316SS, PVC, Kynar®
  • Variable Oil By-pass™ stroke adjustment allows improved valve performance over variable linkage designs.
  • Capacity control options include electric stroke length adjustment and variable speed drives.

High Viscosity “V-Pumps”

Metering Pumps – High Viscosity “V-Pumps”

tubula diaphragm pump


Neptune high viscosity, flat diaphragm “V-Pumps” are designed to accurately meter viscous fluids up to 5000 cP such as polymers and other thick liquids.


  • Handles moderate viscosity fluids.
  • Standard flat diaphragm.
  • Large internal porting with a large, single ball, suction check valve.
  • Capacities to 30 gph (113 lph) at 100 psi (8 kg/cm2).
  • Available in all 316SS with SS trim.
  • Electric stroke control options and variable speed drives.
  • Variable Oil By-pass™ stroke adjustment mechanism provides better valve performance than variable linkage designs.
  • Teflon® diaphragm withstands most chemicals.

Variable Oil By-pass™ stroke adjustment allows an adjustable time delay between the end of the suction stroke and the beginning of the discharge stroke. This delay permits the ball to seat fully before pumping resumes, even in the heaviest liquids, so that pumping accuracy remains high.

Tubular Diaphragm Pumps

Metering Pumps – Tubular Diaphragm Pumps

tubula diaphragm pumpSpecial Application Pump

Neptune Series 500 tubular diaphragm pumps are engineered for viscous fluids up to 20,000 cP and for medium slurries up to 10% solids.

Design Features/Benefits

  • No-clog design. Straight-thru flow pattern eliminates pockets where slurries can settle.
  • Easily handles high viscosity liquids.
  • Double diaphragm is standard.
  • Capacities to 80 gph (302 lph).
  • Control options include electric stroke control and variable speed drives.
  • Standard units with double ball suction and discharge valves. Single ball suction valve is optional.
  • Variable Oil By-pass™ stroke adjustment mechanism provides better valve performance than variable linkage designs.
  • Viton elastomer withstands most chemicals.
  • Elastomer memory and tube shape reduce NPSH requirements, allow more viscous fluids to be pumped.

Series 600 “Dia-Pumps”

Metering Pumps – Series 600 “dia-Pumps”

series 600 dia pumpFeatures

  • Capacities to 240 gph (908 lph)
  • Pressures to 4000 psi (280 kg/cm2)
  • Accepts standard 56C motor.
  • Pump capacity is adjustable by micrometer dial while pump is running or stopped.
  • Capacity Control Options: Electric positioners or variable speed drives are available for automatic capacity control.
  • EZE-CLEAN™ valves are removable without disturbing piping.
  • Variable Oil By-pass™ stroke adjustment allows improved valve performance over variable linkage designs.
  • Hydraulically balanced Teflon® diaphragm eliminates stress.
  • Power train operates submerged in oil for extended service.

Series 7000 Mechanical “Dia-Pumps”

Screen Shot 2013-07-12 at 1.32.43 PMPurpose

The Neptune Series 7000 “dia-PUMP” is a mechanically actuated diaphragm metering pump designed for water, wastewater and process applications.


The mechanical design eliminates the use of contour plates on the liquid side of the diaphragm. The simple, straight through valve and head design allows improved flow characteristics.

  • Self-priming
  • Superior performance when pumping chemicals such as sodium hypochlorite, which can off-gas
  • Suction lift exceeding 20 ft. on water-like chemicals
  • Easily handles viscosities in excess of 5000 cps
  • Maximum capacities range from 12 gph to 300 gph at 150 psi, depending on model