Walk enough quarry sites and you start to see the same patterns. A pump running flat out and moving less water than the operator expected. A good pump working in water it was never intended for, wearing through impellers every few months while everyone treats it as the cost of doing business.

In most of those cases the pump itself is fine. It just was not matched to the duty.

Audex builds two ranges for this work, and they are designed around different conditions. Getting the range right is worth a few minutes up front, because sizing within the wrong range will not fix the problem.

Start with the water

Not the volume. Not the distance. The water itself.

The AS range is built for water: rainwater, groundwater, runoff and wash plant discharge. It can be cloudy and carry fines, but it is still primarily water. These are high-speed pumps running at 3,450 rpm, and they are built to generate head — up to 433 feet on the largest units. For most dewatering duties on an aggregate site, this is the range you will be working in.

The AW range is built for dirty water: silt, sludge, settling-pond bottoms and anything approaching slurry. Every AW pump carries an agitator that keeps solids suspended at the suction point, so material does not pack around the inlet and choke the pump. AW models pass solids up to 30 mm, against a maximum of 20 mm across the AS range, and they run at 1,750 rpm — roughly half the shaft speed of an AS pump.

That speed difference is the point of the range. Wear rises sharply with impeller-tip speed in abrasive water, so the slower AW impeller holds up in gritty service where a faster pump would wear more quickly.

The trade-off is head. The AW range tops out at 104 feet. The AS range reaches 433 feet.

Put simply:

• AW pumps move dirty water over shorter distances.

• AS pumps move cleaner water against greater head.

Each range does something the other is not designed to do, and horsepower does not bridge the gap in either direction.

Sizing an AS pump: head first, then flow

Head is where AS selection starts. A common assumption is that more horsepower means more water, but within a given discharge size the extra power is usually buying pressure rather than volume.

Look at the 6-inch models. The AS 6-4500 is a 60 HP pump moving up to 872 gpm at a maximum head of 295 feet. Step up to the 100 HP AS 6-7500 and maximum flow comes in at 740 gpm, with maximum head at 433 feet. The additional power is doing a different job.

So begin with static lift, add the friction loss through the hose or pipe run, and work from the total dynamic head. Once you have that number, the selection narrows quickly.

Shallow sumps and surface water. The AS 4-370 and AS 4-550 cover low-head, moderate-flow duties: 61 to 80 feet of head and roughly 420 to 450 gpm. Both are light enough for two people to handle with an appropriate lifting strap. For smaller catch basins, look at the AS 2-220 or AS 3-550.

General pit dewatering. The AS 4-1100 and AS 4-1500 give maximum heads of 159 and 183 feet. At comparable power, the 6-inch models trade some head for more flow.

Deep pits and long lifts. Pumping from a working face, static lift can exceed 150 feet before friction losses. That points to the AS 4-2200, AS 4-3000, or one of the high-head 6-inch models.

Bulk transfer and wash plant feed. High volume with modest lift is 8-inch territory. The AS 8-3700 and AS 8-4500 both move up to 1,347 gpm; the AS 8-5500 reaches 1,717 gpm.

Solids handling within the AS range

One detail worth checking during AS selection: solids capacity is tied to head, not horsepower.

The 15 HP AS 6-1100 passes solids up to 19.5 mm. The AS 6-4500, with four times the power, passes 6 mm. Higher head requires tighter clearances, and tighter clearances leave less room for grit. That is a design characteristic rather than a limitation — it is simply worth knowing before you order.

If the water carries solids and an AS pump is still the right fit for the head, the 8-inch family is a good place to look. Every 8-inch AS model passes solids up to 20 mm. On the smaller models, check the solids specification against your water.

Sizing an AW pump

The AW range splits into three groups, and one of them is aimed squarely at quarry duty.

The AW 2-040 and AW 3-075 are 115 V single-phase pumps with aluminium motor bodies — useful on construction sites, but not built for aggregate operations.

The AW 2-150 and AW 2-220 move to full cast-iron construction with high-chrome impellers and agitators. These suit smaller silty duties on a 2-inch discharge.

The quarry range starts at the AW 3-400. From that model up, every pump runs at 1,750 rpm, passes solids to 30 mm, and uses a high-chrome impeller, agitator and inlet plate.

The AW range also uses a side-flow, top-discharge design. It keeps the motor cool when the pump is running partly out of the water and allows a very low continuous running level — useful if you need to draw a settling pond or sump close to the bottom. AS pumps are designed to run submerged, so submergence needs to be part of the plan on that side.

Two practical checks before you order

1. Generator sizing. If the pump will run on temporary power, confirm the generator requirement before the order goes in. Across both ranges, recommended generator capacity is approximately four and a half times the motor rating — so a 60 HP pump may call for around 270 kW, and a 120 HP pump around 540 kW. Starting current is what drives this, and it is easier to sort out now than on delivery day.

2. Weight and handling. Same discharge size does not mean same handling requirement. The AS 4-1500 weighs 317 lb. The AS 4-2200 weighs 815 lb on the same discharge. There is a design step between those two models, and it affects lifting equipment and site prep.

All models discussed here are available in 575 V three-phase 60 Hz — the standard supply at most Ontario industrial sites.

What matters after the sale

Getting the selection right is the first half. What happens eighteen months later, when a wear part fails and the plant is down, is the other half.

That is why we stock Audex parts here in Ontario rather than routing every order through an overseas supplier, and it is the reason behind our 48-hour parts guarantee. A well-matched pump still costs you production if an impeller takes three weeks to arrive.

If you are not sure which range fits, send us three things:

• The required head

• The desired flow

• A description of the water and the solids it carries

That is usually enough to narrow it to two options. We would rather have that conversation before the pump is on site than after.