By John Salmon

The Salmon office staff get a lot of questions about submersible pump installation. So as a Brisbane plumber of 30+ years (who clearly has no life whatsoever!), I’m naturally very excited to do a deep dive on submersible pumps, their uses, installation, and problems to look out for.

Submersible water pumps, aka dewatering submersible pumps, are everywhere. From your septic tank to your rainwater tank, from bringing clean water up from a bore or well to getting rid of liquid trade waste.

So, why would you need your pump to be submersible? And do you need one?

Here are all the answers to common questions we’re asked about submersible pumps for general use, flood prevention at home, commercial and industrial use.

Feeling pumped? I am!

What is Discharge Head and how do you calculate it?

This is the pressure that the pump must overcome to move the liquid through the discharge pipe to reach its destination. It’s generally measured in pascals of pressure or in meters. To get the right pump, you’ll need to know what’s required to overcome the discharge head. If the liquid is being pumped vertically (from underground, for example), you’ll need to know the height that it will be pumped. This is called the static discharge head. The length of the piping, the pump’s flow rate and any additional pressure at the location where the liquid is discharged will need to be taken into consideration, too.

Clear as mud? That’s why choosing the right submersible pump usually means getting an expert plumber (like me) to do some maths. You must get this right or the pump won’t run efficiently, or at all.

Do you actually need a Submersible Pump?

The right flow/discharge capacity, the discharge head, the quality of the pump’s design and the quality of the plumber fitting it all have an impact on how well the pump will perform. Just saying, if you need an excellent plumber in Brisbane, we’re really good at this stuff.

Advantages

  • Cheaper To Run. Because it’s submerged in the liquid it’s pumping, submersible pumps predominantly use kinetic energy to move fluids around – and kinetic energy is free. Who doesn’t like free/cheap energy? In an industrial or commercial setting, these savings can be mind-blowing.
  • Quiet. Noise won’t annoy the neighbours
  • Child- (and fool) proof. Fools do tend to find impressive new ways to be foolish, but as these pumps are submerged and out of sight, they’re less prone to breakage by passing fools (or foolish contractors on site), or interference by bright and curious children.
  • Low Maintenance. A quality submersible pump is completely sealed, corrosion resistant and very, very reliable. Perfect, especially if you’re after one for emergencies like floods.
  • Less Problem-prone. Quality manufacture and installation go a long way to heading off any issues with pumps, but the type of water pump you find at your local hardware store – well, it’s notorious for problems. Leaking and seal problems, power problems – nothing costs more than a cheap pump! Submersible pumps are completely sealed, so a lot of these potential issues are avoided.

Disadvantages

  • Requires Professional Installation. A plug-and-play pump from the hardware store can be installed by anyone. But when it needs fixing, you’ll be calling the sparkie or plumber out. And yes, you’ll be making that call sooner than you think.
  • Reduces Capacity. Depending on the size of the submersible pump, it can reduce the capacity of a tank. Most domestic submersible pumps will mean sacrificing about 50 litres of rainwater in your tank or pond.
  • Requires Some Maintenance. Over time, you will need to replace any seals on your pump. Access is a bit trickier as the unit is kept within the liquid source.
  • Quality REALLY Matters. Yes, submersible pumps are designed to be submerged in liquid. However, a low-quality pump will deteriorate faster, and water will infiltrate the motor. This doesn’t pose an electrical risk unless the pump is faulty or does not comply with Australian EESS quality standards. HOT TIP: never buy a submersible pump on a discount website or unassembled. Not kidding. People do. Darwin Award winners mostly.

Submersible Water Pumps at Home

There are two kinds of submersible water pumps used regularly in Brisbane homes. The first is a permanent fixture with a specific purpose. The second is increasingly popular due to our crazy weather of late, a portable submersible water pump for when the floods hit.

Here are some residential applications for submersible pumps.

  • Suburban Rainwater Tanks and Irrigation Systems. A submersible pump is a more cost-efficient way to pump rainwater into your irrigation system. Learn more about rainwater tank installations.
  • Submersible Pumps for Ponds. Most of our customers choose a submersible pump for backyard ponds because they want a serene, quiet environment. A submersible pump aerates the water in your pond and makes cleaning it much easier.
  • Pools. A submersible pump is an efficient way to empty an over-full pool or a pool requiring lining maintenance, especially if the pool is inground and cannot be efficiently siphoned.
  • Water and Septic Tanks. For Brisbane’s semi-rural residents, a submersible pump is a more efficient option for bringing underground tank water into your home, or to deal with your septic system. We can provide you with a specialised service in areas like Jimboomba, outer Moreton Bay and on the Redlands Islands.
  • Submersible Pumps for Floods. Brisbane used to be all about the droughts, but we’re a flooded city these days. If you’re in a flood hotspot like Deagon or Rocklea, owning a submersible pump can help you move floodwaters out of your home faster to minimise damage and maximise the impact of your stormwater drainage system. The key here is to buy the right pump, with the right flow/discharge capacity, and the right discharge head for your needs. Nothing worse than a useless tool in an emergency! As Brisbane’s trusted stormwater drainage plumbers, we’re happy to talk you through it. Just give us a call.

Commercial and Industrial Submersible Pumps

Sewerage, trade waste, stormwater, irrigation, and safety systems… they all need the right pump to do the job right. And, frankly, whether it’s sewerage or contaminated water, the job needs to be done right. Not just for public safety, but because the laws and fines are HUGE.

Installing Industrial and Commercial Submersible Pumps

Are you upgrading plant and equipment to be compliant with environmental laws? Maybe you’re dealing with liquid trade waste that needs sorting. Your engineers have probably made some suggestions, but you need a professional Brisbane commercial plumber to do the installation plan in line with Queensland laws.

  • Flow Rate and Head. The whole project relies on accuracy in flow rate and “head” measurement. A submersible pump will only work efficiently if these are accurately calculated.
  • Viscosity. How much is your fluid going to resist being moved? The fluid type will impact the type of submersible pump you need. You’ll also need to consider the kinds of solids passing through the pump system. Sewerage pumps, for example, may have different requirements in a large commercial public toilet setting than in a treatment plant. Because people in public toilets do incomprehensible things. Trust me. I’m a plumber. I have seen some things you wouldn’t believe.
  • Environmental Requirements. Legal compliance under Queensland law.
  • Energy Efficiency. High-volume liquid pumping creates a massive energy cost. Submersible pumps help reduce that cost, but your business goals will determine which pump will be most cost-effective over time.
  • The Site. Are there site considerations that will make installation a challenge? Will the pump be operating at an extreme depth? Is the delivery destination vertical or horizontal?
  • Corrosive or Abrasive Materials. Slurry, chemical waste, mineral runoff – anything that can cause damage to your pipe infrastructure must be taken into consideration. Your engineers will have advice, but your professional industrial plumber will know the options available. That’s us, by the way.

But Wait, There’s More! Pump Maintenance and Decontamination

Submersible pumps are generally designed to need less maintenance than other types of pumps, but in a commercial or industrial environment, all plant and equipment needs regular maintenance to make sure everything runs efficiently and complies with industry regulations. Most companies do this on a scheduled maintenance plan that includes:

  • Core Maintenance. Visual inspection and core maintenance of the seals, O-rings and bearings. Diagnose any changes in the overall state of the system including changes in flow rate or an increase or decrease in pressure. Make recommendations for any parts that need replacement due to damage, or manufacturer recommendations.
  • Decontamination. While your team will keep your plant equipment clean, pumps may periodically require full decontamination, especially if they’re moving chemicals, sewerage, or slurry.
  • Compliance. Provide necessary documentation of the inspection for compliance purposes.

Repair Considerations

A permanently affixed submersible pump will usually be more difficult to repair than other models. The pump may need to be completely removed from your system for repair. This can mean a period of downtime.

We recommend you find a reliable emergency plumber who is on the road 24/7 (that’s us), and one with extensive experience working with some of Brisbane’s largest commercial operations (also us). That way, you can be sure that if and when repairs are needed, they’re completed to the highest standard and with the minimum disruption.

Okay, yes… this is my sales pitch. But our services are backed by decades of experience and a reputation we’ve earned through demonstrated expertise and service excellence. You won’t find someone more pumped about submersible pumps than the Salmon Plumbing team! Get in touch today.