Automatic Duckbill Composite Sampling System

This “Simpler Sampler”, from Markland Specialty Engineering, helps municipal and industrial plants monitor effluent by automating the collection of composite samples from tanks, non-pressurized pipes, sumps, sewers and open channels.

The unique system uses compressed air and the rubber Duckbill, acting as a check valve, to collect samples, and allows users to program the controller to sample based on time or by a flow meter. It can collect from multiple sites simultaneously, facilitating the monitoring required for environmental regulatory compliance.

It is able to move samples up high lifts (more than 79ft/24m vertically) and over long runs (more than 98 ft/30m horizontally), even in freezing temperatures. The control box for the compressed air can be located far from the sampling site and requires only an air-line to run to the sampler head. Liquid flows into the submerged sampler head through a bottom inlet (drawn by hydrostatic pressure), up through the rubber Duckbill and into the hoses, until it is equal to the level of the outer tank or sump. The body of the sampler fills only as high as the top fitting for the vented airlines, trapping a pocket of air in its dome. The sampler is now ready for a burst of compressed air, which increases the pressure inside the sampler head, squeezing the rubber Duckbill and causing it to close and expel any large particles back through the bottom inlet. Simultaneously, this forces the complete sample through the lower fitting, up the hose and into the collection bottle.

This system is inherently explosion-proof (no pump; no vacuum system). Lines are blown clear and dry after each sample. Users may call in manual samples at any time without affecting the normal sampling interval. Modular design means components, including small compressors, can be selected and assembled to suit the customer’s sampling requirements. The sampler head is available in aluminium, stainless steel, and PVC, to accommodate specific fluids.