Motor Driven Diaphragm Pumps

Frequently Asked Questions

Controllers & Monitors

What variables can be measured or controlled with ProMinent equipment?

We can measure or control pH, Redox, Free or Total Chlorine, Chlorine Dioxide, Conductivity, Ozone, Peracetic Acid, Hydrogen Peroxide and Dissolved Oxygen.

Can you explain what the different options are using the Ident-code for the D1C controller?

The Identcode for a D1C has 13 parameters that can be specified. The first parameter is the type of mounting such as wall or panel mount. Then the operating Voltage must be selected. The measured variable is the parameter being measured such as pH, chlorine, Redox ? The next selection is the connection of measured variable, which selects how the sensor is wired, such as an SN6 connector. The correction variable selects whether there is pH or temperature correction. The next variable is feed forward capability. This signal can be used for metering proportional to the flow rate. The control input allows control by contact closure. The signal output function can be set up as measured, controlled or correction variable. The power control variable pertains to the alarm functions and how and what they control. The pump control option is set up for whether pumps will be controlled. The control characteristic sets the pump up for proportional control band or the more sophisticated PID control. The interface is not used at this time. The last variable allows for the selection of the language.

What is feed forward control?

This signal can be used for metering proportional to the flow rate.

What do I need to order with a D1C?


Where are conductivity controllers most commonly used?

Conductivity controllers are used in industries including, paper, pharmaceutical, plating, electronics, breweries, power production, and plating. Two very popular applications are bottle washing and cooling towers.

What type of controller is the Dulcomarin?

The Dulcomarin controller is designed exclusively for swimming pools. The basic unit has 2 measuring inputs for measuring and controlling pH and chlorine or pH and redox potential. Two ProMinent pumps such as betas or gammas can be connected to the Dulcomarin to add chemicals for a maintenance free pool.

Customer Service Procedures

What is needed for a return for credit?

Before contacting ProMinent, We ask that you provide your sales order confirmation number or our original purchase order number to expedite this process.

What is the procedure?

Contact the CSD department. RMA paperwork will be sent to you via email. The containment free certification must be filled out an attached to the OUTSIDE of the package. In the event that the equipment was unused, ?None / unused? should be written on the CHEMICAL DESCRIPTION line.

How much credit will be issued?

If the equipment is in like new condition, full credit is issued minus a 25% restock fee. This fee covers the expense of processing the credit and returning the product to stock. The restock fee can be waved at a manager?s discretion.

Who pays the freight?

Typically, the freight charges are the responsibility of the customer unless otherwise noted.

What is needed for a repair?

Before contacting ProMinent, We ask that you provide your equipment serial number and model code in order to expedite this process. We also request a description of the symptoms of the repair with as much detail as you can provide. This will aid in the troubleshooting of the equipment and assist in expediting the repair.

How much will it cost?

After the equipment is evaluated, A quote for the repairs will be emailed. This repair quote will include a minimum labor charge of $90.48 NET. If the repair is determined to be not cost effective, and is scrapped at ProMinent, the labor charge will be waived. If the pump is inspected and returned without repair, the minimum labor charge will apply. If a replacement pump is purchased, the fee will be waived. Please let your customer service representative know the purchase order number in this instance so the repair can be closed.

Who pays the freight?

Typically, the freight charges to ProMinent are the responsibility of the customer unless otherwise noted. Freight charges are covered if the equipment is repaired under warranty.

What are the terms of ProMinent?s warranty?

Unless there are obvious signs of neglect or abuse, Drive units are covered for 2 years, Liquid ends are covered for 1 year, accessories are covered for 1 year , Dulcometers (D1C/D2C) are covered for 1 year. Complete warranty information can be found on page 15 of the 2012 catalog.

Sending in Orders

Please send all orders via Email to PFCUSORDERS@PROMINENT.US Please DO NOT send purchase orders to customer service representatives. This could cause a delay or misplacement of your order.

Standard Lead Times for Products / Expediting

Standard lead times are listed below. If you need an order expedited, please contact your customer service representative. Please be aware that overnight shipments receive priority over ground shipments. Gala/Beta/Concept - 3 days Sigma series - 5 days ProMus - 2 weeks Dulcometer 3-4 days

Pumps & Accessories

What are the primary advantages of a solenoid driven metering pump?

The pump drive has only one moving part, the armature shaft. Generally, the less moving parts, the more reliable the pump. Solenoid pumps are very good for low pressure applications and compensation for line voltage fluctuations are excellent.

How do I use a pump nomograph?

Find the nomograph page that applies to the model of pump needed. Mark the backpressure present on the lower diagram marked Capacity. To determine the correction factor, take the determined backpressure in bars and follow upwards until the curve is reached. At this point go vertical to the left, until the correction factor can be read. Divide the required capacity by the correction factor to get the capacity in ml/min. or L/h. Place the result in the middle scale marked Capacity. Once this value is placed on the capacity scale, a ruler may be used to reflect the stroke setting and the frequency setting.

What are the most important considerations when working with metering systems?

The most important considerations when working with metering systems are: A. Discharge pressure B. Stroke Frequency C. Suction lift D. Altitude E. Chemical compatibility

When discharging to atmosphere, what steps will improve repeatability of dosing?

Installing a spring in the discharge valve of the pump gives some improvement, but for the maximum improvement, a backpressure valve should be installed at the end of the line.

What should I adjust the backpressure valve to?

Never exceed the maximum operating pressure of the pump. When working with a positive displacement metering pump, the discharge must be at least 15 psig higher than the pressure on the suction side of the pump.

To what pressure should the pressure relief valve be set?

The pressure relief valve should be adjusted within the range and not to exceed the maximum operating pressure of the pump. The pressure relief valve is designed to prevent an over pressure condition with the pump. For example, if the pump maximum operating pressure is 50 psig, the pressure relief valve should be set at 50 psig. or below to insure proper operation of the pump. Over pressure conditions are the prime reason for pump failure.

When should flooded suction be used?

Flooded suction should be used when: 1. Fluid being pumped out gases. 2. Fluids have high specific gravity. 3. High stroke frequency is needed. 4. The pump is operated in a high altitude region. 5. The application requires a large storage tank where suction lift is impractical.

When working with liquids in hydraulic systems, what considerations must be taken into account?

The primary considerations are Viscosity, Specific Gravity, Vapor Pressure and Temperature.

What parts are included in the in a complete liquid end kit?

The parts included in the complete liquid end kit include a pump head, diaphragm, valves, backplate and mounting screws.

What is the purpose of the foot valve?

The foot valve is comprised of a weight to help hold it straight and vertical in the chemical tank. It is also a check valve to keep a positive direction of flow. This valve also aids in repeatability and priming of the pump. It has a strainer to prevent particles from being drawn into the suction line. Small particles may cut or tear the diaphragm. The foot valve also has a connector set to adapt it to the suction line. The foot valve should be kept off the bottom of the tank and should be mounted in a vertical position. A foot valve is required in most applications using suction lift.

What is the purpose of the injection valve?

Injection valves are used to connect the pump discharge line to the point of injection. Injection valves are not to be used as an isolation device or for antisiphon protection. The injection valve gives a 7 psig backpressure for non-critical metering.

What is the difference between a single stage and a two-stage float switch?

A single stage float turns off the pump when the switch activates. A two-stage float activates the first level that can be used as a low tank level warning indication. When the second switch activates, the pump is stopped.

What is a Multifunction valve?

The Multifunction valve is a very versatile product that generates constant backpressure to insure constant metering. The device has a built in antisiphoning valve that prevents siphoning of chemicals into vacuum lines, water lines with Venturi effect, or negative discharge head applications. The built-in pressure relief valve, protects the pump, lines and equipment against over pressure in the event of dead heading. It has a built-in priming valve that relieves pressure in the discharge line allowing the pump to prime. The discharge drain valve allows fluid to be safely drained back to the tank.

How does a metering monitor function?

Meter monitoring uses a proximity switch that trips with every fluid pulse. The pump compares discharge strokes to fluid pulses sensed. If flow is not sensed in 8 strokes, or on the gamma/L the set number of strokes, the pump stops and a fault is indicated. It will sense loss of flow due to an empty, blocked or leaky suction line, deadhead or diaphragm failure. A proportional meter monitoring will sense volume failure below 20%, or the set volume.

What is the fault annunciation and pacing relay options?

The fault annunciation relay either drops out or pulls in on a pump fault. The pacing relay pulls in on a pump fault and generally connects to pace a secondary pump at the same rate as the primary pump.

What is the purpose of a pulsation dampener?

A properly sized pulsation dampener reduces pulsations by 90% or more and gives a nearly laminar flow. It reduces acceleration and deceleration head loses.

What are the functions of an accumulator and how does it differ from a dampener?

An accumulator reduces pulsations along with reducing acceleration and deceleration head loses. The accumulator has no separation of fluid from air. The chamber may eventually fill with liquid and need to be drained.

What is a diaphragm rupture monitor and how does it work?

The backplate between the drive and the pump head has a weep hole. A tube connects the weep hole to a small cylinder. If the diaphragm ruptures, liquid drains from the weep hole into the small cylinder. The cylinder has a float switch that activates when it sees as little as 10 mL of liquid. The contacts can be set up as normally open or normally closed.

What are the individual color coded wires on the Universal control cable used for?


How do I replace the pump diaphragm?


I have received a spare parts kit and I am having trouble removing the old diaphragm. Can you give me some additional advice for removing the diaphragm?

Remove the liquid end by loosening four head screws. Do not remove it all the way. Turn the stroke length adjustment down to 0% and grasp the liquid end. Then, slide it away from the threaded holes so the screws do not make contact with them but still has a hold on the back plate and diaphragm. Then turn the assembly counter-clockwise. The diaphragm should loosen off the solenoid shaft with little resistance. If the diaphragm does not loosen, penetrating oil should be applied to the surface where the diaphragm and solenoid shaft meet. Let it sit for a couple minutes and lightly tap diaphragm and slightly with a plastic hammer. Then follow the above specifications again.

When running Hydrogen Peroxide with suction lift, the system develops air lock. How can this problem be eliminated?

Install a self-degassing head on the pump, and use flooded suction. Keep the suction line short.

Can I turn down a ProMus pump below 30% stroke length?

(YES) because the diaphragm is completely supported with hydraulic oil you can turn down the ProMus pump below 30%. There are some limitations though and it depends on the size of the pump and the pressure. Please contact ProMinent for Performance Graphs for each pump size.

Can I use a Variable speed motor for a ProMus pump?

(NO) because this pumps has internal mechanically actuated valving for the hydraulics and they are pressure dependent. We have found that when you use a variable speed motor it loses torque at lower RPMs. This can cause several problems such as: Not restarting after a stalled condition, Loss of flow or intermittent flow at lower RPMs, overheating of motors.

Can I pump High Viscosities or off gassing materials or combustible materials with the ProMus pump?


Can I re-prime the hydraulic system myself in the field?

(YES) there are videos on U Tube of diaphragm replacement and Priming the hydraulic system.

Can I use the internal pressure relief to regulate process pressure?

(NO) there internal relief is designed to protect the pump and diaphragm only. Always use a external Back Pressure and pressure relief valve set below the internal pressure relief of the pump. If the pump runs in internal relief for longer than 24 Hrs. you need to must replace the diaphragm to prevent rupturing.


What is DPD and how are these tests run?

The most widely used DPD tests are done using the colorimetric system. The amount of Chlorine in the water causes the color to change to magenta. DPD causes an oxidation of the chlorine, which changes the color. The intensity of the color is directly proportional to the chlorine concentration. (DPD stands for N, Ndiethyl-p-phenylenediamine). DPD reacts in much the same way with other oxidants, including bromine, iodine, ozone and permanganate.

What is the difference between an Amperometric and a Potentiometric sensor and which ProMinent sensors fall into each category?

The Amperometric sensors measure a change in current, while the Potentiometric sensors measure a change in Voltage. The Potentiometric sensors are shielded and are susceptible to line noise and other interferences; pH and Redox sensors fall into this category. All of the other sensors supplied by ProMinent are Amperometric. Note: ProMinent offers many accessories such as mA transducers and impedance converters, which can convert potentiometric output for long runs.

Are there certain applications where Dulcotest sensors should not be used?


What is the best way to clean sensors?

Glass sensors should be soaked in a dilute 1% Hydrochloric acid solution for several hours with periodic gentle brushing. then rinsed with water. The steps are the same for most membrane sensors, but the electrolyte must be replaced after cleaning. (The CTE sensor membrane cannot be cleaned; it must be replaced).

How long can pH probes be stored?

Preferably not longer than ¼ year; they are ageing even unused.

How should pH probes be stored?

Preferably at 10-30°C constant; frost (winter) and high temperatures (summer) should be avoided during transportation

What does ?double junction? mean?

Two diaphragms with intermediate electrolyte to avoid poisoning of the reference electrode (Ag+/AgCl).

When do you recommend an open diaphragm (PHEX)?

With high soil content (suspension, emulsion) and high conductivity

What type of pH probe in municipal waste water?

The PHER (with PTFE ring diaphragm)

Why should the PHER/RHER not be used in drinking or swimming-pool water?

The zero point is not stable, moves slowly away.

What type of probe in electroplating applications?

PHEP/RHEP in clear measuring liquids and PHEF when containing hydrofluoric acid and pH acidic (under 4)

Cleaning of the glass membrane of a pH probe?

Never mechanically! Only chemically! With diluted acid for inorganic deposits (e.g. lime, rust). With alkaline cleaner, solvent for organic deposits (oil,fat)

Cleaning of the ceramic diaphragm (with pH and Redox)?

Also mechanically, e.g. with key file; otherwise as glass membrane

Which is the value of the electrical resistance of a ceramic diaphragm?

Typically 3 k?

What is an "alkali error/sodium error"?

Less slope with high Na+ content/pH-value (NaOH)

What is a "calomel" reference electrode?

Hg/Hg2Cl2 in KCl instead of Ag/AgCl in KCl ? poisonous ?meanwhile unusual!

When do you recommend an impedance converter or transmitter on top of the pH probe?

With low temperatures and wide distances to the measuring device

What is Redox?

Reduction / Oxidation is a principle that measures the solutions strength to either reduce or oxidize materials in a solution. The term Redox stands for simultaneously occurring reduction and oxidation process in aqueous solutions. In an oxidation process, electrons are transferred from the substance to be oxidized to the oxidant. Simultaneously, in oxidizing the substance, the oxidant is reduced. Oxidants are electron acceptors and reducing agents electron donors. Oxidizers are normally Caustic. Reduction agents are normally Acidic. Measurement of Redox potential is pH dependent.

What is free residual Chlorine and how is it measured?

Chlorine exists in water as Hypochlorous Acid (HOCL) and Hypochlorite Ions (OCL). It reacts readily with ammonia and some nitrogenous compounds to form combined chlorine. It can be measured by DPD1. Note: Most DPD test kits change the pH of the sample to between 6.5 and 6.8.

What is combined residual Chlorine and how is it measured?

Chlorine existing in a chemical combination with Ammonia, Nitrogen, or organic Chlorine compounds. It can be measured with DPD3. Note: Chlorinated wastewater and industrial effluents normally contain only combined chlorine.

What is total Chlorine and how is it measured?

Total Chlorine is free Chlorine plus combined Chlorine. It can be measured by DPD4.

I am using a CLE Chlorine sensor in my system. My solution contains a surfactant and my chlorine reading drifts slowly downward.

The surfactant may clog the sensor membrane. This electrode was designed for swimming pools and water of similar quality.

Can I use the CLE Chlorine sensor in Deionized water?

No, the electrolyte will be diluted by diffusion and because the sensor is Amperometric, it needs some conductivity to function.

Can I use the CLE sensor in water with a high turbidity level?

No, the recommended range of the sensor is 100 to 300 mg of hardness. Reduce the turbidity by filtering and then run the test samples. The sensor membrane can be clogged by a highly turbid sample.