Concrete Pump Blowout: Analysis of Water vs Compressed Air

In this article we will analyse the benefits of using water instead of compressed air when blowing out concrete pump lines, as well as how to contain, manage, and treat this wastewater safely.

What is Concrete Pump Blowout?

Concrete pump blowout is a cleaning method used to clear residual concrete or partial blockages from concrete pump lines using either compressed air or water. This is done to prevent residual concrete from hardening/stetting inside the pump lines, as this causes blockages.

What makes Blockages in Pump Lines dangerous?

Blockages stop pours, causing delays and harming efficiency. This however, is not your main concern when your pump lines become blocked. The trapped energy caused by blockages results in extremely high pressure, which greatly increases the risk of pipes bursting.

The bursting of a concrete pump line can be catastrophic, with the safety of workers being jeopardized as well as the hoses and pipes being expensive to replace.

To avoid the bursting of concrete pump lines and the on-site safety issues that come with it, concrete pump blowout is a necessity.

How are Concrete Pump Lines Blown out?

Concrete pump blowout is carried out by first inserting a sponge ball (commonly known as a 'pig') into the delivery hose at the start of the pipeline. The ball is then pushed through the pump lines by either by water or compressed air. This pushes residual concrete/blockages and out of the other end of the hose.

This residual concrete must be captured and contaminated (when using either method) as the highly alkaline concrete slurry can be extremely damaging to the environment.

For more information on the environmental impact of concrete wash water or slurry, please visit :

Concrete Washout: What It Is, Site Rules & Best Practices

Why is using Compressed Air more dangerous than using Water when Blowing Out Concrete Pump Lines?

Hose Whipping

Using compressed air to remove blockages in concrete pump lines causes a buildup of pressure. When the blockage is cleared, the pressure drops and the sudden expansion of air (as it's no longer being compressed) instantly increases its volume.

This causes the concrete slurry to blast out rapidly, which can cause the hose end to whip violently- if not properly secured- with enough force to have the potential of causing severe trauma or damage on impact.

Caustic Burns

Due to the high alkalinity of concrete slurry or residue, it causes caustic burns when coming into contact with exposed skin. When blowing out concrete pump lines using compressed air, concrete residue is blasted out at significantly higher speeds than when using water, as well as spraying it over a larger area.

When using water to blow out concrete pump lines, the release of residual concrete slurry is considerably slower and far more controlled, meaning the likelihood of of accidental contact is greatly reduced.

High-Velocity Debris

The high-pressure release when a blockage is suddenly cleared by compressed air in concrete pump lines can cause hardened concrete, debris, or the sponge ball, to be blasted out of the hose at high speed. This can pose a severe threat to safety on-site.

Alkaline Mist

When blowing out concrete pump lines using compressed air, the air can break up residual concrete slurry into an alkaline mist, and suspend cementitious particles and other contaminants in the air.

These contaminants can be irritants to the nose, throat, and lungs of workers on-site, with repeated exposure being a cause for significant respiratory health effects.

Whilst the residual concrete slurry generated by using water to blow out concrete pump lines still contains the contaminants and dangerously high pH levels, treating water is much more manageable than trying to treat air. In the next section of this article, Kelly Tanks provide an ideal solution and best practices for the containment, management, and treatment of these highly alkaline, suspended solids laden wastewater.

Concrete Pump Blowout Lid

The Concrete Pump Blowout Lid Attachment locks into place on top of our Adsorption Sack Frame, creating a secure containment solution for the safe and efficient blowout of pump lines.

To adapt the Sack Frame for blowing out, we designed a Blowout Insert that slots into the Sack Frame to help absorb the substantial force generated when a concrete pump line is blown out. Many will also fill the tank for the additional weight to provide extra stability.

Adsorption Sack Frame

Our Adsorption Sacks enable the retention of solids, in this case residual concrete, whist allowing effluent to filter and drain. The Frame can suspend sacks in or out of water.

We've specially designed the Sack Frame to allow the fast flow of water whilst retaining solids and and adsorbing contaminants. This makes it ideal for washing concrete trucks and equipment off into, as well as other onsite waste disposal.

This means that you have more than a safe, efficient solution for blowing out concrete pumps. You can remove the Blowout Lid Attachment to use the Adsorption Sack Frame for concrete washout.

pH control is simple but manual, with KT Reducer, protecting the environment from harm and helping you to remain compliant.

For any further questions on the Blowout Lid or Sack Frame, please email us at:

info@kellytanks.co.uk

Or call us at 01889 508944