Save the Date!

Panner would love to invite you to join us for a plant tour of one of the Grundfos facilities.  Through acquisitions and their commitment to developing new products, Grundfos may be the fastest growing pump company in the world right now.  Their legacy brands include; Peerless Pump, Yeomans-Chicago Pump, Paco Pump, and Enaqua UV.  Grundfos is opening up the former Yeomans-Chicago plant for an open house on Wednesday, June 3rd from 10 am to 3pm. The plant location is 3905 Enterprise Ct, Aurora, IL 60504.   We'd love to have you as our guest.  For more information or to RSVP, simply leave your name in the comment section below, with the number of people who will be coming with you in parentheses.  We will follow up with you with complete details of the event.

Product Announcement: Type 578 Lug Style Butterfly Valve from GF

Georg Fischer has expanded it's butterfly valve product line to include the new Type 578 plastic-bodied lug-style valve. This valve incorporates many of the industry-tested design features that our butterfly valves are known for:

1. The double eccentric disk design disengages the disk from the seal while the valve is opening and closing, resulting in reduced component wear and decreased required operating torque.

• Reduces required operating torque by approximately 50%

2. The glass-filled polypropylene outer housing provides UV and chemical resistance while increasing impact strength.

3. The truly non-wetted 316 stainless steel shaft is protected by a precision bushing assembly featuring a redundant o-ring design.

Features

• Size: 2”–12”
• Body: Glass filled PP with overmolded SS316 lugs
• ANSI 150 bolt pattern
• Materials: PVC, CPVC, PP, ABS and PVDF
• Stem: 316 stainless steel
• Seal: EPDM or FPM; PTFE seals available upon request
• Operation: Bare shaft, lever, gear
• Actuation: Electric and pneumatic

To learn more, contact the folks at Panner @ 815-469-8333, or e-mail: info@panner.com

Chemical Feed Pumps: Mounting Flexibility

Chemical feed pumps are the key component of many industrial and utility processes. These include:

• Cooling tower water treatment
• Boiler water management
• Water and wastewater disinfection
• Process chemical addition
• Cleaning chemical addition

These pumps are best applied along with ancillary items such as back pressure valves, calibration columns and pulsation dampeners to improve their operation or help control a treatment system.  Because of this, the chemfeed system can take up a large footprint in areas where space is at a premium. 

Pumps that give you mounting flexibility are important to optimize your use of space.  Pump manufacturers are introducing modular mounting designs that allow you to directly wall-mount their product.  With that configuration you can design an entire system like that shown below. 

We have both "standard" systems, and the capability to custom make systems to fit your unique space.  To learn more about how to maximize your floor space by vertically integrating your chemfeed systems, contact Steve @ 815-412-5683, or send an email to shapiro@panner.com

Eductor Mixing Systems

Process mixing within tanks is typically done using rotating blade electric mixers.  An alternative to this uses a recirculation pump with eductors.  In certain applications, eductors are a more appropriate method to mix tanks. 

The venturi effect creates a low pressure zone within a nozzle when flow cross-section is reduced. This low pressure area is used to draw surrounding fluid into the nozzle for a mixing effect.  Eductor nozzles    are installed on a manifold within a tank and connected to an external (or internal) circulation pump.  The venturi effect typically induces the addition of four gallons of liquid to every one gallon of pressurized liquid that flows from the pump. 

Rather than using a rotating mixer with blades, a pump and eductor system can be used to mix liquids in odd-sized tanks. Another advantage of educators is their availability in a variety of thermoplastic materials so they can be used with corrosive liquids.  Eductors are available in polypropylene, CPVC or  PVDF.  They can also be sourced in stainless steel or iron.

Recirculation manifolds are also a convenient location for chemical injection ports.  So if you are adding chemicals  to an existing tank you can inject and mix them easily.   Another advantage of eductor mixing is that the incorporation of 3-way valves in the recirculation system allows you to pump the fluid to a remote destination after the mixing is complete.

Eductors are inexpensive and require little maintenance compared to mechanical mixers.  This is especially valuable in applications requiring special corrosion resistant materials.

Passing Gas (Part 3)

The newest technology to combat vapor lock conditions common in small chemical dosing pumps is through the use of a stepper motor.  You may wonder how a stepper motor would help, but you can bet I'm gonna share that with you.

Traditional solenoid dosing pumps use an electromagnetic solenoid to shift the shaft connected to the diaphragm.  A spring returns the shaft to a "relaxed" state.  These pumps regulate the dosed quantity by adjusting stroke length and / or stroke frequency. But reducing the stroke length does create disadvantages regarding dosing accuracy. In cases where the dosing pump cannot operate at 100% stroke length, both the suction and discharge valves will suffer from reduced performance leading to inefficient dosing. Variations in stroke frequency also lead to non continuous dosing.  As there are many possibilities of adjusting those two settings (stroke frequency vs stroke length) to get the same output, many times an optimal setting will be found through continued trial and error.

By using a stepper motor, the volume dosed is altered by the discharge stroke speed while continuously utilizing 100% of the stroke length - which leads to optimum dosing accuracy and better handling of degassing liquids.  How?  Well as you can see in the graphic below, assuming we have the pump set to a 100% stroke length, both pumps have very similar outputs when pumping @ 100% frequency.  But as you slow the pump down, the difference becomes more apparent.  The traditional pump at the top shows how there is more time where the pump is doing nothing between strokes, where as a pump with the stepper motor, indicated by the graphic on the bottom, is discharging the entire time in between suction strokes. The stepper motor also improves system performance: through continuous dosing of chemical, lower pulsation in the system, and by completely filling and evacuating the pump cavity.

It's the complete filling and evacuating of the pump cavity that also makes it have fewer issues when pumping a liquid that off gasses.  Let's face it, if we ran at 100% stroke & frequency all the time, we would have very few problems even with the traditional dosing pump because most of the gas can be pulled in and evacuated in a single full stroke.  But most of the time these pumps are selected because it's known that the demand will be no more than X gph, so we size the pump knowing it can meet that max and be turned down to meet the real required volume.  It's when people begin to mess with lower volumes that most issues arise.  Most people understand the need for continuous dosing, so they don't mess with the frequency, instead opting to change the delivery volume by adjusting stroke length.  Then problems begin to arise.  In fact if you have a traditional dosing pump, you can probably walk over to it right now and see where the stroke length adjustment knob may have some different pattern, like a solid bar, going from 0 to 20 or even 30%, like the pic below.  The purpose of that is to indicate that the pump shouldn't be run that low due to the inconsistencies or inaccuracies of flow at those low stroke lengths.  And accuracy is why metering pumps are used.  

By utilizing the 100% stroke length all the time and varying flow by slowing down the discharge stroke, stepper motor pumps are proving to have many advantages over traditional dosing pumps, including being able to more effectively dose chemicals that off-gas.  If you'd like to read a case study, click here.  If you'd like to see and learn more about this technology, then contact Steve to setup a demo for you. 

Passing Gas (Part 2)

This week let’s talk about the evolution of Auto degassing heads.  At one time the introduction of the integral bleed valve was thought to be revolutionary.  And while it greatly assisted in the priming and operation of the pump, it wasn’t a true fix to being able to handle fluids that off-gas because it still requires an operator to see that the pump has vapor locked, and then open the integral bleed valve to purge off the gas.   

(Integral bleed valve indicated)

What I consider to be the auto de-gassing head, is the one with 3 ports; one on bottom (suction), one out the back (discharge), and one out the top (vent). 

  

First time users of this pump will often pipe it incorrectly as they will assume the top port is discharge and the one out the back is the vent.  However, that is switched, and for good reason.  These pumps are designed so the gas will rise to the top port and get continually pushed out.  The downside is that some fluid will naturally get cycled out the vent as well, thus these pumps must be de-rated in order to more accurately establish their likely flow rates. The fluid is then discharged out of the port configured out of the back of the pump in a horizontal manner.  This style pump has greatly improved the dosing of chemicals that off gas.

In recent years, some manufactures have begun to automate the, previously discussed, bleed valve portion of the pump.  The pump is designed to be able to notice when there is air in the head of the pump, and a relay then causes a solenoid to open the bleed valve.  The pump then goes to max frequency and the air gets purged through the pump during the pre-set timed sequence.  The pump can be programmed to operated this sequence as a preventative measure, or corrective action.  This has proven to be a pretty effective yet costly addition, as it requires an additional solenoid, the use of a relay, and a dedicated panel. Yet to correct or prevent the headaches associated with vapor locking your pump, is often worth that additional price.   

Next time we’ll talk about the newest manner in which metering pumps are passing gas…

Understanding wet-tap assemblies

My intent was to do a blogpost on the diaphragm style metering pumps with regards to pumping fluids that off-gas, but between customer emergencies, holidays, and all the new information I have received in my research, I just haven't been able to complete part 2. So the "Passing Gas" discussion may become a much longer segment than I originally anticipated. In the meantime, Steve Purucker was kind enough to do a write up on Wet-tap assemblies. So here you go:

Wet-Tap Assemblies

Wet-tap or Hot-tap sensor assemblies enable operators to safely remove and reinstall a sensor through a ball valve without interrupting the flow in a pipe.  They also allow the removal of sensors from the sidewall of tanks without the need to lower the liquid level.  This is very useful for applications that require periodic maintenance or calibration. 

Wet-tap assemblies require pipe shutdown for the initial installation.

Hot-tap assemblies can be installed without interrupting the flow.

Here are some examples of wet-tap assemblies from the George Fischer/Signet product line:

The Signet 3519 Wet-Tap Valve mounts directly onto standard Signet installation fittings. The 3519 Wet-Tap Valve consists of a flange and a support plate that threads onto the pipe fitting insert, and a PVC ball valve through which an extended length sensor is inserted into the pipe. It allows you to remove a paddlewheel flow sensor for cleaning or maintenance while the pipe is flowing.

The Signet 3719 pH/ORP Wet-Tap allows installation and removal of pH or ORP electrodes, even under process pressure, without the need for process shutdown during routine electrode maintenance and calibration. Automatic process isolation is achieved during electrode retraction with a double O-ring seal on a unique and compact retraction assembly; no separate valve is required.

Insertion magmeters can be used in pipes from 2” to 102” in diameter and can be inserted through a standard 1.5” coupling.  A full bore ball valve allows removal for cleaning without process shutdown.

Steve Purucker, PE has been a team member at Panner for more than 25 years.  His vast knowledge of all our product lines makes him a great resource.  Please feel free to contact him at 815-469-8333 if you have any questions.