How to Change Out a Melter Pump
There are several reasons why a melter’s pump might stop working. The most common reasons are clogging of the ball and seat from foreign matter such as carton dust, and the actuator clogging due to dirty or oily air. No matter what the reason, if your pump stops pumping it needs to be replaced. Obviously, it much more cost effective to change out a pump then to replace the entire unit. However, it is not always easy to switch out a pump, especially if you are new to the line. Below are a few tips to help ease you through the process.
- Make sure the circuit breaker on the front of the unit is set to OFF once the applicator has reached normal application temperature.
- Shut OFF the input air to the pump.
- Set the pump regulator to zero and trigger all guns to relieve system pressure.
- When removing the old pump, rotate it slightly to break the suction and then pull it straight up and out.
- When installing the new pump, make sure to torque the screws 15-16 ft-lbs.
- Connect the pump electrical plug to tank receptacle and turn tank back on.
- Once the tank board reads that the tank has reached set temperature, wait 15 minutes. This will allow the glue around the pump hydraulics to get to temperature.
- After waiting 15 minutes, reinstall the air regulator and connect the airline and activate air.
If you have any further technical questions and want to speak with a technical sales rep, please call (561) 272-5442 or email sales@ussefl.com.
Melt Rate vs. Pump Rate
When purchasing a hot melt adhesive system, it is important to know your desired melt rate and pump rate. It is also important to understand the difference.
All Universal Systems SE ProBilt™ tanks are equipped with a 14:1 ratio pneumatic pump assembly. Pneumatic pumps are most common and have a maximum pump rate of 75 lbs. per hour. No matter what the tank capacity is, whether it is 12 lb., 15 ob., or 20 lb., the pump will max out at 75 lbs. If you need to pump more adhesive then that per hour, you will need to transition to a gear pump system with a larger tank capacity.
The melt rate is the rate at which the tank will melt the adhesive you put into the reservoir. This is where the tank capacity comes into play. Before moving forward with any hot melt adhesive system, first you need to understand how many pounds you need to melt per hour. The melt rate is dependent on how many hoses and gun applicators you are running and how many boxes are sealed per minute on your packaging line. The most common tank capacity is the 20 lb. (10 Liter) ProBilt™ 20, with a melt rate of 23 lbs. per hour. If you are only running one line with one hose and gun applicator, then you may only need the 15 lb. (7 Liter) Probilt™ 15 which melts 18 lbs. per hour.
A common misconception is that the on-demand autofill system, the ProBilt™ Phoenix, will have a larger melt rate and pump rate. That is incorrect. The tank capacity on any auto fill system is the same as a regular tank such as the ProBilt™ 20. However, the advantage to the auto fill is that the line operators will not have to watch the adhesive level in the tank as closely. The vacuum system connected to the tank will sense when the adhesive level is low and automatically fill the tank. This helps eliminate dry running and pumps will last longer. However, the pump rate on this system will still max out at 75 lbs. per hour.
For additional information about melt rate and pump rate on all of our ProBilt™ tanks, please call (561) 272-5442 or email sales@ussefl.com.
Piston Pump Troubleshooting
There are several things that can cause a piston pump to stop working. The most common reason is that it is clogged. Unfortunately, not all line operators take the time to close the lid on a glue tank. With a lot of carton dust in the air at any facility, this dust gets into the glue pot and melts in with the glue. When the pump shifter runs to pump the glue from the pot into the hose, that carton dust gathers around the pump which can cause it to seize. The simple solution to this is to make sure that all shift line operators are diligent about closing the tank covers, that’s why they are on there.
If carton dust is not your issue, and the pump fails, below are a few other possible causes and the corresponding solutions.
- Adhesive not sufficiently heated – check the tank temperature and required melt temperature of your adhesive and set accordingly.
- Inadequate or no input air to pump – increase the air pressure from the plant air supply and see if the pump will run.
- Dry running – when a tank drops below a certain adhesive level in the pot, the pump does not have enough glue to operate at full capacity. The glue that runs through the pump acts as a padding so that the shifter does not pound against the top and bottom of the pump itself. When that padding is less, the pounding shifter can cause damage to the magnets and create an issue with the shifter. The only solution to this is to get a new shifter and potentially invest in an auto fill on-demand system that fills the glue into the tank for you, leaving less pressure on the line operators to fill the pot.
- No Tank Screen or Clogged Tank Screen – the tank screen lives at the bottom of the tank and is the first line of defense against any foreign debris getting into the pump. Sometimes the tank screen gets removed or never cleaned. That can cause debris build up and seize your pump. It is easily cleaned by lifting out of the empty tank and then cleaning the tank with Purge Plus™.
- Clogged Tank Filter – the tank filter screws into the side of the tank and filters the glue after it leaves the tank. If the tank filter is clogged, then the adhesive will back up in the pump, causing the pump to seize.
- Pump solenoid is not on – if the tank is not within 35 degrees of the setpoint temperature on the control panel, the pump solenoid will not turn on. Check the setpoint temperature and make sure it is correct. If the setpoint temperature is correct and reading properly, then it might be a failed solenoid that needs to be replaced.
If you go through all of these troubleshooting steps and still have an issue with your pump, please call (561) 272-5442 or email sales@ussefl.com.