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Integral Orifice System
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IOS6 Integral Orifice System

  • Reliability is greatly enhanced with the presence of a tell-tale system of vent valves that detect leakage around the orifice or bypass valve
  • The removable orifice carrier allows convenient servicing of the orifice and seals without disturbing the piping
  • Unimount design mounts directly to a 2" pipe stand permitting servicing or removal of the transmitter without disturbing flow or piping
  • Can be mounted directly in-line
  • Slotted hex handles discourage tampering but operate with a simple 90º turn
  • Adjustable packing nut stops interport and stem leakage
  • Large 5/16" straight-thru, roddable porting
The D/A Integral Orifice System, model IOS6 is a complete mounting, metering and manifold system that accepts any standard DP transmitter and utilizes the standard Foxboro orifices. This unique system was designed around recommendations from customers experiencing problems with other integral orifice systems.
Operation Specifications
Normal Mode
Block valves open and bypass closed
IOS6 Normal Mode

Bypass Mode
Block valves closed and bypass open
IOS6 Bypass Mode

Zero Mode
Bypass open and one block valve closed
IOS6 Zero Mode
Materials of Construction:
 Body: 316SS
 Plugs: 316SS
 Valve Seals: Teflon or Ryton
 Vent Valves: 303SS with Kel-F seat
 Bleed Valves: 303SS body with 316SS trim
 Handles: 303SS
 Orifice Carrier: 316SS with Teflon seals

Exotic materials: Hastelloy C, Monel, Alloy 20, etc. consult factory.

Max Ratings:
  3000psi @ 150ºF
  1500psi @ 220ºF
  3000psi @ 150ºF
  1500psi @ 450ºF)

 Inlet / Outlet:  1/2" FNPT
 Instrument:  Flanged on 2-1/8" centers

Flow Rate:
 The IOS6 utilizes all Foxboro standard orifices up
 to 0.159" which gives 2.25 GPM @ 400ºW.C.
 Refer to Foxboro flow charts
How to Change Orifice
How to Change Orifice
  1. Open bypass valve and close both block valves
  2. Remove orifice carrier from valve body
  3. Remove orifice from end of carrier with cushioned pliers or some other method that will not damage orifice
  4. Remove and check process seal for damage - replace if necessary
  5. Reinstall process seal and gently tap new orifice onto end of carrier with care
  6. Reinstall orifice carrier into valve body
  7. Open both block valves and close bypass valve
Units are supplied with 2 U-Bolts and 4 transmitter mounting bolts

Code  Integral Orifice System
IOS6  Flanged (instrument) x 1/2" FNPT (process)
| Code  Seal
| T  Teflon
| R  Ryton
| | Code  Material
| | SS  Stainless Steel, 316
| | | Code  Options
| | | OCJ  Jeweled Integral Orifice
| | | |  
Model Number


D/A Manufacturing Co., Inc.
Hwy 86 East or P.O. Box T
Tulia, TX  79088-0920 USA
Phone: (806)995-2316
FAX: (806)995-4601