Needle and Stopcock Valves

Needle and Stopcock (also called Labcock or Chemcock) valves typically have a small inside diameter and are used for precise flow regulation. Fluid flow is controlled by lowering and raising a needle-shaped plunger that fits into a seat. The plunger is connected to a screw and as the screw is turned, flow between the seat and the plunger is possible; however, until the plunger is completely retracted the fluid flow is significantly impeded. Since it takes many turns of the fine-threaded screw to seal the valve, precise regulation of the flow rate is possible, even down to a few drops per minute. These valves are well suited for instrumentation and laboratory use, especially when a constant, calibrated, low flow rate must be maintained for some time. Since many turns of the valve stem are required to completely open or close the valve, they are not used for simple shutoff applications.

Standard Sizes

1/4" - 1/2" diameter

Sizes and materials are brand specific. Click on a manufacturer below for available products. Please contact Aetna Plastics for pricing information.

To view material Corrosion Guides, visit our Technical Specifications page.


  • Size Range: 1/4"
  • Materials: PVC
  • Products: Labcock Valve
  • Size Range: 1/4"
  • Materials: PVC
  • Products: Needle Valve and Chemcock Valve
Georg Fischer
  • Size Range: 1/4" - 1/2"
  • Materials: PP and PVDF
  • Products: Type 522 Needle Valve
  • Size Range: 1/4" - 2"
  • Materials: PVC, CPVC, PVDF and GFPP
  • Products: Needle Valve and Stopcock Valve
  • Size Range: 1/4" - 3/8"
  • Materials: PVC and CPVC
  • Products: Labcock Valve