One of our customers is a global thermoplastic elastomer manufacturer. They relocated several pumps that they used in their previous plant in Duluth to their new location in Buford, Georgia. Due to the poor piping network in their new facility, there was excessive suction pressure to the pumps. The result was excessive cavitation, noise, and much more limited flow. This customer had existing competitive internal gear pumps that were to deliver 25 GPM of Parulux oil, which could not be delivered with existing pumps. After recommended suction piping changes, we supplied three Viking SG1026 external gear pumps direct driven by a 900 rpm motor and customer is getting more than 25 GPM flow and no cavitation issues.
When we took a look, it was clear to us what needed to be done. We made recommendations for them to change their piping in order to reduce suction pressure to the pump. We also recommended they start using a different style of pump. We were even able to use some of their existing material on their existing pumps and modify it.
Our customer increased their suction pipe size to 2 inch and reduced their maximum suction lift to 25 feet, and changed pumps to recommended Viking SG1026 2-inch pumps with same size motors for existing power, and these pumps exceeded required flow of 25 GPM discharge.
After all of our recommendations and a different pump, now everything works great.
Many of my customers in north Georgia who produce coatings, printing inks and light weight chemicals and typically use air operated diaphragm pumps are always asking me what we can offer for metering, dosing or being able to remote operate their dispensing operations.
Most of these customers also use positive displacement gear pumps and after learning the initial purchase prices of a variable speed positive displacement with their limited capital budgets are looking for options.
IR ARO recently launched their new Electronic Interface EXP air operated diaphragm pumps that have solenoid control rather than an air valve assembly.
The electronic interface pumps can also be supplied with optional cycle counter to track end of stroke feedback and pump data. The PE electronic interface pumps allow maximum flow rates with minimum air consumption (on average 3%+ less). The PE pumps also have lube free design with fewer parts than the standard pump with the exclusion of the air valve assembly with inclusion of solenoid valve control.
Many of my customers have several AOD pumps in operation for their dispensing requirements that historically needs intensive manpower to operate equipment, and now ARO offers a multi-pump controller that communicates with the new ARO electronic interface pumps which eliminates intensive operating with remote operation and also provides safer control.
Let us schedule a survey of your existing pumps and how they are operated, pending metering or dosing requirements, and discuss how these new improved ARO pump controls can help.
Many of my customers ask “WHY DO I NEED A SUCTION STRAINER FOR OUR NEW PUMP?”
Below are the primary reasons:
VIKING internal gear PD pumps have tight strict internal clearances and if the inlet fluid could contain a high particulate concentration from pipe debris or fluid hardening that may cause restriction in pump clearances specified causing excessive heat and potential cavitation that could cause short pump life and the downtime to inspect and repair pump may be cost prohibitive to your production requirement. A suction strainer is a relatively inexpensive item compared to cost of new or repaired pump and should be considered as an insurance investment. Centrifugal pumps that have enclosed trimmed impellers can also see blockage with potential same outcome from cavitation or short pump life from heat bearing failure. An inlet suction basket strainer or Y-strainer can be supplied with several filter mesh liners for specific size particulate seen. If your fluid has high particulate due to fluid composition then a no mesh basket can be supplied with approximate 3/16” perforated basket. Look at your cost of lost production time or pump repair time and you will see the minimal cost of a suction strainer is justified.
Many fluids may be harmed from pipe scale seen on inlet of pump or from the pump bushings or other internal pump parts that contain carbon or iron. Again, an inlet pump strainer will protect your fluid from these damaging materials.
VIKING PUMP has partnered with EATON STRAINERS for inlet simplex and duplex strainers with many different materials of construction and port configurations. See link for more information.
VIKING LIDEASE strainers is a proven simplex suction strainer supplied for many years has an easy opening cover is another option. See link for more information.
If your production process cannot allow downtime to clean or replace internal strainer baskets then the EATON duplex strainer is best recommended option.
If you consider your fluid a clean fluid and inlet piping not an issue then a suction strainer may not be needed.
Pump leakage has become more critical in recent years because of environmental concerns, fugitive emissions, handling of carcinogen materials and loss of valuable products. Acid based fluids typically have viscosities similar to water, and may have no or limited lubricity properties. Internal gear pumps or external gear pumps work best with Newtonian type fluids. Shear sensitive fluids are not a good application for gear pumps. The complete list of shear sensitive fluids is endless. Fluids that provide good fluid film between bushings and idler pin have best results with gear pumps. Acid based fluids also may not be compatible due to materials of construction and seals supplied with gear pumps. VIKING Pumps has a stainless liquid vane pump (LVP) for light weight fluids and a non-metallic mag drive external gear pump (CMD) for hazardous fluids that have Newtonian properties and require (leak free) seal-less operation.
As advised above, water based fluids with no lubricity will cause short pump life due to the fluid not providing an adequate film between the bushings and idler pin. Fluids with heavy and large solids will also cause short life for wear to gear pump internals. If fluid suction strainers can be used and if fluid has some lubricity gear pumps will provide positive flow and long life.
Centrifugal pumps with non-clog impellers are typically best pump for high trash fluids.
NPSH (Net Positive Suction Head) is critical for proper operation of any positive displacement pump. Net Positive Suction Head (NPSH) can be defined as two parts:
NPSH Available (NPSHA): The absolute pressure at the suction port of the pump.
NPSH Required (NPSHR): The minimum pressure required at the suction port of the pump to keep the pump from cavitating.
NPSHA is a function of your system and must be calculated, whereas NPSHR is a function of the pump and must be provided by the pump manufacturer. NPSHA MUST be greater than NPSHR for the pump system to operate without cavitating. Put another way, you must have more suction side pressure available than the pump requires.
Please see VIKING Pump website reference document UNDERSTANDING NET POSITIVE SUCTION HEAD for more detailed explanation.
Our inside engineering staff or myself or our other area representatives can assist with proper pump selection and application design.
Many customers have to submit for corporate / management budgetary pricing for new or replacement compressed air equipment for pending fiscal budget approval. This monetary amount is compiled for the estimated costs of replacement compressed air equipment or based on estimated additional air required for pending production processes.
With improved technology relating to compressed air audits being able to report current compressed air operation with actual air and pressure requirement for typical daily or weekly operation, determining if existing compressed air system is controlled properly, energy costs of existing equipment, and savings that can be made via an air leak audit and leak repairs that can reduce actual air demand for pending air requirements, below are a few items customers (large and small) should consider with compressed air equipment purchase.
If customers review the power costs of equipment in their plants, they will see that the compressed air equipment is most likely the biggest user and the discussed air leak audit or air system audit will provide a better understanding of current air requirements and / or if additional equipment is needed. If air demand varies during a typical day, an air audit will also assist with adding additional air storage for intermittent needs or show that a variable speed air compressor may be best option versus adding an additional fixed speed air compressor.
Many customers when adding compressed air equipment or expanding production process with new compressed air system tend to work with plumbing or mechanical contractors with specification to stay with current black iron or copper piping and fittings. The installation of compressed air or vacuum pump equipment is typically part of the scope of purchase for pending plant upgrades or new projects.
The upfront costs of piping material and the compatibility with existing piping is normally primary concern versus the time and labor of installation.
Many compressed air manufacturers are now supplying new technology lightweight aluminum piping with quick connect fittings and elbows such as GARDNER DENVER's Quick-Lock Tubing. The structural integrity of the new aluminum piping or tubing meets current ASME standards and unlike black iron pipe, no pipe saddles or hangers are needed. The new aluminum tubing is supplied in standard lengths and cut on site easily for mounting with quick connect fittings. Black iron pipe installations may also require special lifting equipment due to weight of pipe and hangers required. This not required for lightweight aluminum.
The price difference for old school black iron pipe and fittings versus aluminum lightweight pipe and quick connect fittings is approximately 10 percent higher for the aluminum but where a normal installation of black iron pipe upgrade may take 3 to 4 days, the new aluminum lightweight piping is typically installed in one day; drastically reducing the downtime and labor for iron pipe install.
Some customers expressed concern over the availability of the new aluminum piping and fittings compared to iron, galvanized, or copper pipe. GARDNER DENVER keeps extensive inventory in local warehouse in North Carolina. Many local mechanical contractors are also keeping the new aluminum piping and fittings in their inventory.
One local customer who has seen the benefits of this new technology is International Paper in Lithonia GA. They upgraded their plant piping network with the new aluminum piping. Their current air system has three air compressors, one GARDNER DENVER RDS cycling type air dryer, and a 5000 gallon vertical air receiver. The time frame for complete piping installation was two days.
The technical specifications for the GARDNER DENVER Quick-Lock aluminum tubing (reference documents GA-QLT-100 or GA-BLT-100) show maximum pressure of 220 psig and maximum temperature of 176 deg F. The maximum pressure for vacuum pump installations is 29.6 inches hg V. These ratings meet most ASME compressed air or vacuum system requirements.
Many customers because of a lack of plant floor space or due to safety (noise / heat related) requirements install their compressed air stations outdoors.
If this is you? It is highly recommended you use some type of weather protection to keep blowing rain, snow, ice or dust from entering your air compressor intake. NEMA 4 controls and TEFC motors and sound enclosures can be supplied by the manufacturer but some type of protection such as a lean-too cover or awning is always recommended.
Several customers in my area use a metal canopy or a pitched roof cover on concrete slab next to an exterior building wall and have either fence wall around the area or some will use tarp walls, put up primarily in wintertime, to trap heat from the compressor.
For cold weather operation, I have pasted below an excerpt taken from one of the GARDNER DENVER service manuals:
Figure 2-3 – COLD WEATHER INSTALLATION INSTALLATION FOR COLD WEATHER OPERATION (Figure 2-3) - It is recommended that the unit be installed inside a shelter that will be heated to temperatures above freezing (32 F, 0 C). This will eliminate many of the problems associated with operating units in cold climates where freezing rain, drifting snow, freezing condensate and bitter cold temperatures are encountered.
Refer to Gardner Denver Engineering Data Sheet 13-9-411 for the advantages of using AOL desktop gold customer service the heat recovered from your rotary compressors. This heat recovery could easily pay for an adequate shelter for the unit.
When an outside installation must be made, the precautions required will depend on the severity of the environment. The following are general guidelines for outside installations:
Cold Weather (Down To +10 F, -12 C)
1. Be sure all drains, traps, and control lines, including pressure transducer lines are heated to avoid freezing of condensate. Heat tape with thermostat control is generally satisfactory for this purpose and can be obtained at various local plumbing or hardware outlets at nominal cost.
2. If an air-cooled aftercooler is to be used, provisions to bypass the aftercooler must be made. Since cold air contains very little moisture, successful operation can be achieved without the aftercooler.
3. Provide at least some simple shelter such as a plywood windbreak to protect against drifting snow.
4. Use only Gardner Denver AEON 9000 SP lubricant.
5. Monitor the unit carefully during start-up and operation to be sure it is functioning normally.
6. Specify NEMA 4 enclosure for electrical devices.
Another item to consider when mounting your compressed air station outdoors is your Compressed Air Receivers. If your air receivers are mounted ahead of your system dryers, bulk condensate will collect in bottom of tank and typically an automatic electronic or float drain is needed. Many companies do not run compressors on the weekend and this fluid that is collected in the bottom of tank and possibly in the air lines feeding the tank will freeze during winter conditions.
To protect yourself from future headaches it is recommended to insulate your outside pipe and also the condensate drain used on tank. There are condensate drains available with internal heaters that will also solve this problem.
As far as air filters and air dryers (refrigerated and desiccant) mounted outdoors – please see below excerpt taken from cagi.org (COMPRESSED AIR & GAS INSTITUTE) website regarding the myth of air dryers installed outdoors.
Myth: Any dryer (refrigerated or desiccant) can be installed outdoors.
Fact: All standard dryers are designed for internal installation. However, many are often installed outside, (with a lean-to roof in some cases and without a lean-to roof in some cases). Outside installation is acceptable provided there is lean-to roof with freeze / snow protection, blowing rain protection, and a roof / ceiling high enough to avoid hot air re-circulation. Outside installation of standard dryers with no roof is not recommended.
Low ambient protection such as heat tracing drains and interconnecting piping can be supplied at the time of purchase to solve this problem.
Another problem some of my customers with regenerative dryers encounter is that when the dryers are mounted in a secondary building with outside piping between buildings they have seen poor dew points or shorter desiccant life. Condensation may be formed from outside non-insulated piping or pipe drops and the downstream desiccant dryers see excessive amounts of inlet condensate that will not allow the desiccant to work properly or corrode the desiccant from excessive water.
To potentially protect yourself from this problem, it is HIGHLY recommended to have a secondary air receiver ahead of the dryer that will catch bulk water or condensate and reduce or eliminate the moisture collected on outside piping exposed to varying wintertime and summertime conditions.
It is also true that a secondary air receiver should be included for refrigerated air dryer installations for outside piping for the same downstream moisture problem.
Air receivers are a low cost item compared to downstream instrumentation or precision valves used. In fact, a small air receiver can be as low as $ 200.00.
Many customers are becoming energy conscious and are reviewing existing production equipment to look for ways to save energy. One major item of consideration is the cost of compressed air. For fluid transfer requirements, many customers will use an Air Operated Diaphragm pump.
For a typical 2" AOD pump to transfer 50 GPM of light weight fluid with a discharge pressure requirement of between 40 to 50 psi and an inlet air pressure of 70 psi, it will require approximately 50 cfm of air (this converts to approximately 12 BHP). If the fluid is viscous and has a higher discharge pressure requirement, the inlet air pressure for the AOD pump can increase to 100+ psi and will require 25 percent+ more flow.
This was evidenced by my customer, RUSTOLEUM in Decatur GA who manufactures coatings. They were using a 3” AOD pump to transfer a viscous 1500 cps, high particulate metallic coating that is very abrasive. The AOD pump had an inlet air pressure of 120 psi and a discharge pressure of approximately 30 psi which resulted in a discharge flow of 40 GPM. The required cfm of air was approximately 60 cfm (15 BHP).
Due to the pulsation seen on piping and valves, they were also using a BLACOH 2” pulsation dampener. Because of the abrasive nature of fluid, the AOD pump required service with new wetted parts every 3 to 4 weeks which was totaling around $500 per repair.
The customer wanted to expand production with a required flow of 60 GPM and would need two 2” AOD pumps to accomplish this, which would be around 50 to 60 cfm for 30 GPM @ 120 psi (converts to 15BHP).
In an effort to reduce both the maintenance costs as well as the energy costs, a VIKING LS4124A 3” internal gear, positive displacement pump was supplied. We c-face mounted the pump to a speed reducer and drove the package with a Premium Efficiency 7.5hp 1750 rpm motor. The pump is typically supplied with carbon graphite bushings but we replaced those with hardened iron bushings; and we also converted the pump from a mechanical seal to packing, expecting a short seal life due to the abrasive nature of the fluid.
The Viking LS4124A pump is supplying a transfer rate of 65 GPM and is seeing reduced parts replacement. The transfer rate was reduced by almost 30% using the Viking PD pump compared with the AOD pumps. And the power requirement was reduced by 50 percent.
Based on this improved performance, Rustoleum has now converted their West Virginia plant from AOD pumps to VIKING positive displacement pumps for this same sand based, high viscous fluid.
RUSTOLEUM still uses various AOD pumps for their light weight water based fluids.