NRS™ Needle Control Valves

Low Flow Gas & Liquid Flow Control Valves

Models 8503F / 8504F

The Brooks® NRS™ (non-rising stem) flow control valves are designed specifically for extremely low flow gas and liquid applications. Straight and 90° angle pattern models in stainless steel are available. Ideal for rotameters with needle valves, the line allows needle valve flow control by adjusting a sliding tapered needle. This prevents sticking caused by foreign matter in the fluid. These flow control valves are particularly suitable for precise control requirements and possess a high turns-to-lift ratio. The flow is constant for any given stem position.

Six needles with different tapers provide a wide choice of flow ranges. Needles and orifices can be changed without removing the valve body from the line (two different orifices are used, one for needle sizes 1-3, another for sizes 4-6).


  • Smooth non-reversing flow characteristics
  • Constant flow at any given stem position
  • Fifteen turns full open to full close provides high turn-to-lift ratio for excellent resolution
  • Six interchangeable needle tapers, each increases capacity by an approximate factor of three
  • O-ring seal cannot be damaged by overtightening
  • Panel mounting nuts included as standard
  • 1/8″ NPT connections integrally machined into body
For Use With
  • Mass Flow Meters
  • Variable Area Flow Meters

Product Type



Designed for Extremely Low Flow Applications
Straight and 90° Angle Pattern Models Available
Wide Choice of Flow Ranges

Flow Range (Full Scale Capacity)

See Capacities & Pressure Drops Table in Data Sheet

Max Pressure

Stainless Steel Model: 1000 psig

Max Temperature

Stainless Steel Model: 250oF (120oC)

Connection Types

Standard: 1/8″ female NPT – integral
Optional: 1/8″, 1/4″ compression fitting; 1/4″ female NPT; 1/4″ ID hose type adaptors


See Dimensions Figure

Materials of Construction

316 Stainless Steel

Size 1-3: Stainless steel and Teflon®;
Sizes 4-6: Stainless Steel

Valve Needle
316 Stainless Steel

Stainless Steel

Viton® fluoroelastomers

You may also like…

    Solicitar información

    Estoy de acuerdo y he leído el aviso legal.

    En cumplimiento de la LOPD 15/1999 de 13 de Diciembre, le informamos que sus datos podrían pasar a formar parte de un fichero propiedad de la empresa Gometrics S.L. Usted tiene derecho de acceso, rectificación, oposición y cancelación que puede ejercer mediante escrito a la dirección anteriormente indicada. Por la presente autoriza expresamente a la compañía a que le remita información sobre sus servicios a la dirección de correo electrónico indicada en el formulario. La información ofrecida en esta página web es meramente orientativa y no es, en ningún caso, vinculante.