WLD1500 Inverted Bucket Liquid Drainers with Strainers

The WLD1500 Series Inverted Bucket Liquid Drain Traps are recommended for the removal of liquids from compressed air systems. A scrubber wire is used to keep bleed hole on top of inverted bucket from clogging due to oil that may be present in the water being drained. Oil mixed with water is typically found on compressed air systems.
When there is condensate in the system, the inverted bucket inside the liquid drain trap rests on the bottom due to its weight; with the valve in the open position. This allows liquid entering the trap to be discharged through the seat orifice located at the top. When air enters the trap, the bucket floats to the surface and closes off the discharge valve, containing the air in the system. Eventually, air is bled off through a small hole in the top of the bucket and the bucket sinks; repeating the cycle.
  • Hardened stainless steel valves and seat
  • Only two moving parts
  • Scrubber wire in air vent of bucket
  • Discharge orifice at top of trap reduces potential for clogging
  • In-line repairable

Catalog Spec Sheet (pdf)
I&M (pdf)

ModelSizeTypeMax PMO (psig)


WLD1500 Inverted Bucket Liquid Drainers with Strainers are recommended for the removal of liquids from compressed air systems.

Determine the capacity (lbs/hr) required at the specified differential pressure. Locate differential pressure on capacity chart; move down column to capacity required. Make sure to select the correct model based on the maximum inlet  pressure.

Capacity in lbs/hr is based on differential pressure across the drainer. Select a model with an equal or higher PMO (max. operating pressure) than the maximum inlet pressure to the drainer. If the pressure to the drainer exceeds the PMO, the drainer may not open. If discharging to atmosphere, the differential pressure is equal to the inlet pressure.

Required to drain 200 lbs/hr at a differential pressure of 5 PSI. The maximum inlet pressure is 30 PSIG.

Select Model:
WLD1521-13-N, 3/4” NPT, with strainer, capacity up to 220 lbs/hr based on 5 PSI differential pressure.