Brooks Instrument Control Valve - Manual (Page 5)

1-1
Section 1 Introduction Installation and Operation Manual
X-VA-8503-eng
Part Number: 541B087AHG
March, 2008
Needle Control Valves Models 8503 and 8504
1-1 Description
Brooks ® NRS (Non-Rising Stem) Needle Valves are designed specifically for
low flow gas and liquid applications. Straight and angle pattern models in
Brass or Stainless Steel are available. Five different interchangeable
connection fittings can be used with each.
Models 8503 & 8504 are supplied with an NRS control valve. It features a
positive, direct mechanical means of adjusting a sliding tapered needle
which virtually prevents sticking due to foreign matter in the fluid stream.
These valves are particularly suitable for the precise control requirements in
chromatography. The flow is constant for any given stem position. Saw-
toothing is eliminated. Six needles with different tapers provide a wide choice
of flow ranges for all models. Each increases capacity by an appropriate
factor of three. Needles and orifices can be changed without removing the
valve from the line. (Two different orificies are used - one for needle sizes 1-3,
another for size 4-6.)
1-2 Specifications
Capacities and Pressure Drops
Maximum Operating Pressure
Brass Model: 600 psig
Stainless Steel Model: 1000 psig
Maximum Operating Temperature
Brass Model: 180°F
Stainless Steel Model: 250°F
Connections
Standard: 1/8" Female NPT - Integral
Optional: 1/8", 1/4" compression fitting; 1/4" female NPT; 1/4" ID hose type
adaptors
Dimensions
Refer to Figure 1-1
Maximum Capacity
Needle Orifice (Std. cc/min.)
Taper No. Type Helium Air Water
1 300 150 4
2 Small 700 350 10
3 (0.041") 1,400 600 20
4 6,000 2,400 80
5 Larger 18,000 6,800 200
6 (0.093") 55,000 22,000 650
Capacities measured with 10 psig supply and an atmospheric
pressure exhaust. Flow capacities will vary for different gases,
liquids and pressures. Consult factory for further information.