PORTER Variable Constant Differential Flow Controller

The Porter Model VCD 1000 Flow Controller is precision-engineered to control low gas flows at constant mass flow rates regardless of changes in downstream pressure. The VCD 1000 maintains a preset pressure differential across a laminar flow element. Turning the fine-pitched adjusting stem varies the force on an internal diaphragm, which alters the differential pressure across the laminar flow element, thereby changing the flow rate. This design yields extremely linear flow output in relation to stem rotation and virtually eliminates the sawtoothing associated with valve-based controllers. The laminar flow elements are available in full scale flow rates from 5 sccm up to 1500 sccm (He @ 70°F and 50 PSIG).

Design Features & Advantages

  • Delrin® adjusting stem with 56 pitch threads.
  • Turns vs. flow relationship is linear.
  • Bubble-tight shut-off
  • Full scale flow rates from 5 SCCM up to 1500 SCCM (He @ 70°F and 50 PSIG)
  • Replaceable inlet filter included.
  • Standard panel mount configuration.

Specifications
Capacities - see chart on previous page.
Ratings – Maximum operating pressure: 250 psig; Maximum operating temperature: 160°F; Pressure Drop required: 15 psi minimum.
Performance – Control Accuracy: 0.3% of instantaneous flow rate. Adjustability: 0-100% of flow over 14 turns.
Connections – 1/8” compression fitting (brass) with aluminum body; 1/8” compression fitting (stainless steel) with SS body.
Dimensions – Refer to diagram

Materials of Construction
Controller Body- Aluminum or stainless steel.
Controller Diaphragm- Fairprene® BN-5029 or stainless steel.
Orifice- Brass with aluminum body; 316 stainless steel with stainless steel body.
O-Rings- Buna N or Viton.
Filter- Aluminum with aluminum body; stainless steel with stainless steel body.

Capacities

Maximum Flow Range* Flow Element Size Number Color Code on Flow Element**

* Flow ranges stated are based on helium gas at a 50 psig supply pressure

** Color-coded flow element packages appear on aluminum units only. Stainless Steel flow controllers have flow element size etched on the flow element holder.
5 cc/min
8 cc/min
10 cc/min
15 cc/min
25 cc/min
35 cc/min
45 cc/min
60 cc/min
95 cc/min
110 cc/min
144 cc/min
180 cc/min
535 cc/min
465 cc/min
750 cc/min
1060 cc/min
1600 cc/min
5
8
10
15
25
35
45
60
95
110
144
180
400
465
750
1000
1500
Gold Anodize w/Red Dot
Blue Anodize w/Red Dot
Blue Anodize
Silver Anodize w/Blue Dot
Red Anodize w/Silver Dot
Black Anodize w/White Dot
Blue Anodize w/Green Dot
Red Anodize
Gold Anodize
Green Anodize
Silver Anodize w/Red Dot
Silver Anodize
Black Anodize
Black Anodize w/Silver Dot
Silver Anodize w/Green Dot
Black Anodize w/Red Dot
Black Anodize w/Green Dot