FAQ

The most common cause is the poor alignment of the pump and motor shafts. This condition may be corrected by the use of a dial indicator (or such alignment device) to indicate any amounts of misalignment. Since the rubber insert is actually the weakest point of a pump coupling, it handles the misalignment thus preventing premature damage to other rotation parts of the equipment.

Grouting not only maintains proper alignment of the pump/motor but also assists in the reduction of possible vibration. The grout increases the overall mass of the base, thus providing an isolation benefit to the piping system.

A condensing boiler should be considered only when the inlet water temperature to the boiler is at or below 120 degrees F for extended periods of time. Once the return temperature exceeds 120 degrees at the boiler inlet, the high-efficiency advantages of the boiler are greatly reduced.

Low water return temperatures can be eliminated in various different ways. By the use of valves (manual or automatic), water can be blended to raise the temperature to the desired range. To determine the best solution for you, please contact an ONCO professional.

Sounds like a cavitations problem. Please see the above questions concerning NPSH.

The suction diffuser provides the installer the opportunity to eliminate the requirement of a distance not less than 5 times the pipe diameter before entering a pump from an elbow. It also allows for any pipe reduction to be made at the pump inlet to ensure that potential NPSH problems don't develop.

The elimination of air in the system is extremely important. While air is used in older conventional systems, most systems used today require that all entrained air be eliminated as fast as possible to avoid problems. Even in systems where air is used as a cushion for an expansion tank, the air most be forced to one part of the system to compensate for temporary water level fluctuations.

The answer is yes but with caution. Since VFD's cause the motor speed to fluctuate, additional heat is built up in the motor windings. If the motor is older, it may not have the insulation required. It's always a good idea to talk with the motor manufacturer before attempting. At the very least, try to install the VFD as close to the motor as possible.

Volume tanks are designed to simply add additional volume to a system to allow for proper system operation.

Plate & Frame exchangers should be used any time there is a temperature cross that takes place within the unit. They can also be used in non-temperature cross applications is space is an issue.

As water is heated and cooled in a heat exchanger, air is separated. This separation allows for a vacuum to be formed which will result in damage and premature failure if the tubes.

NPSH stands for "Net Positive Suction Head" and sometimes is referred to "Not Pumping So Hot". NPSH is the net suction pressure available at the pump inlet. If the available NPSH is less than that required by the pump, many serious problems can result. Excessive vibration can occur when sections of the impeller are handling vapor and the other sections handling liquid. Probably the most serious problem is pitting and erosion of the pump parts, resulting in reduced pump life. This is caused by the collapse of vapor bubbles as they pass to the regions of higher pressure. Excessive noise and vibration usually accompany this cavitations phenomenon. As the vapor bubbles collapse, the adjacent walls are subjected to a tremendous shock from the inrush of liquid into the cavity left by the bubble, This shock actually flakes off small bits of metal and the parts take on the appearance of having been badly eroded. This erosion shows up not at the point of lowest pressure where the bubble is formed, but further downstream where the bubble collapses. The energy expended in accelerating the liquid to high velocity in filling the void left by the bubble is a loss, and causes the drop in head associated with cavitations. The loss in capacity is the result of pumping a mixture of vapor and liquid instead of liquid. Water, for example, at 700F increases in volume about 54.000 times when vaporized, and thus even a slight amount of cavitations will reduce the capacity. A pump operating with insufficient available NPSH will often pump spurts of liquid. This is caused by the following chain of events: As the pump is started, the liquid accelerates in the suction nozzle until it reaches the capacity at which it is to operate; as it accelerates, the friction losses increase and lower the absolute pressure until the liquid flashes into vapor; as soon as this happens, the pumping action is reduced, and the flow decreases. With the decreased flow, the losses are lower, the absolute pressure is higher, and the liquid does not vaporize. This causes the pump to start pumping again. This increases the flow, reduces the pressure etc. until the whole cycle is repeated and results in an erratic flow rate with spurts of liquid being thrown from the discharge pipe.

The name Oslin Nation comes from the actual name of the company’s founder. His name was Oslin "Ozzie" Nation. When Ozzie was born, it was common to name your first born child using the mother’s maiden name as the child’s first name. Hence Oslin Nation was named and the company still bears it today.

Since we have several different style pumps in the B&G line, we first need to clarify what you have:

• Is it In-Line or Base Mounted?

Now that we have determined what style of pump you have, we can narrow it down. Always look for the manufactures tag located on the pump. If it is a base mounted pump, it will be riveted on the base itself. An inline pump will have a tag fixed to the volute or impeller housing.

• What if the tag has been removed?

If the tag has been removed, the pump has a six digit casting number located on the volute of the pump (the part the water goes through). It usually starts with the letter “P”. All B&G pumps will have this casting number. We will also need the horsepower and voltage of the pump. This information is located on the motor itself.

Since we at Oslin Nation are suppliers of pumps, we will need a certain amount of data to get you the correct pump. We first will need to know if the pump will be base mounted or in-line. Once this is determined, we need to know what the gallons per minute (GPM) and total feet of dynamic head (TDH) the system requires. GPM is the how fast the water is moving and TDH is the measurement of how much pressure is required to move that water. We can use PSI as a substitute for TDH. Since most of us are not engineers, you will need to know this information to let us use our pump expertise to your advantage. We can help you with these requirements on some applications, but an engineer is always a good person to ask.