Canalta DBB Orifice Fitting

Double Block & Bleed for unmatched safety without sacrificing Quality, Accuracy or Performance

  • PROTECTION FROM HIGH PRESSURES & TOXIC FLOW MEDIA
  • ACCURATE FLOW MEASUREMENT
  • HIGHEST QUALITY MANUFACTURING
  • AVAILABLE AS FITTING ONLY, RETROFIT OR COMPLETE AGA-3 OR ISO-5167 METER RUN

The Canalta DBB Orifice Fitting brings the unmatched safety of double block and bleed functionality to the already exceptional quality and performance of the Canalta lineup of orifice fittings.

Two valves separate the operator from the flow line - no need to block in the meter run with multiple ball valves. With separate equalization and venting for the upper and middle chambers, toxic or high pressure emissions through the top, putting personnel in danger, are virtually impossible in the rare event of lower valve failure.

Designed after HSE HSG 253 Cat 2 Isolation, and built to meet or exceed ASME and ANSI specifications, as well as to comply with the latest editions of AGA-3 / API 14.3 or ISO 5167, the Canalta DBB Orifice Fitting provides accurate flow metering over a long service life and superior protection from high pressures and toxic flow media.

Retrofitting Orifice Meter Installations provides added safety without the added cost of full equipment replacement. The DBB’s middle section can be installed on any existing Canalta Dual Chamber Orifice Fitting, or custom fabricated for any Daniel® Senior® Orifice Fitting, bringing double block and bleed functionality to orifice meters already in place.

Pressure Gauges on the upper and middle chambers help the operator assess equipment status. Local pressure readout can indicate valve failure, vent blockages and other dangerous system malfunctions. For added protection, Canalta Gauge Pro blowout preventers are installed between each of the gauges and fitting body.

Automatic Valve Latches can be fitting to one or both of the valve operating shafts. Requiring a manual reset before the valve may be opened, this security accessory provides an added opportunity for safety assessment and operator awareness. The ability to padlock the latch also brings additional security to fiscal flow measurement applications.

The Soft Seat Valve Seal is available for all DBB Orifice Fitting models. Effective in all scenarios, this unique design enables a bubble-tight seal between the three chambers without the need for frequent valve lubrication. The specially machined seal channel helps prevent O-ring dislocation, and the O-ring seals incorporated are available in a wide variety of compositions. The DBB Orifice Fitting is also effective with standard grease seals.

HNBR O-ring Seals on the body sections and seal bar come standard with all Canalta DBB Orifice Fittings. This feature eliminates nuisance gasket maintenance and clamping bar screw breakage, while providing superior sealing capability. The O-rings incorporated are standard shelf sizes and can be supplied in a wide variety of compositions. Gaskets are also available and can be used when preferred or required.

Eccentricity of the Orifice Plate Carrier is fully accessible and adjustable from the exterior of the Orifice Fitting. Tamper proof sealing is done on request.
Technical Specifications
Design...................................
  • Orifice fittings supplied in Canada are built in accordance with the ABSA Quality Control Program.
  • Industry Canada Approval Number AF-0014.
  • In compliance with ASME 16.34 and ASME 16.5, ASTM specifications, AGA-3 Latest Edition and ISO-5167.
Body Materials...................................
  • A216 WCB, A216 WCC, A352 LCC, A358 CF8M, A995 Gr4A, A995 Gr6A, Custom
Internal Parts...................................AISI 4130 Carbon Steel, 316 or A351 CF8M Stainless Steel
Sizes and ANSI Class...................................
  • 2" through 12", 150 through 2500 ANSI raised face flange
  • 14" through 16", 150 through 1500 ANSI raised face flange
  • 18" through 30", 150 through 600 ANSI raised face flange
  • 600, 900 and 1500 flanges also available in RTJ face flange
U/S D/S Connections...................................
  • Flangeneck design (weldneck U/S, flange D/S)
  • Flange x flange
  • Weldneck both end
Internal Bore Size...................................40, 60, 80, 100, 120, 160 and custom sizes
Sealing Compounds...................................
  • Seal bar - HNBR O-ring standard, gasket optional
  • Shafts - Teflon packing standard, HNBR O-ring optional
  • Inner valve - Grease seal standard, HNBR O-ring optional
  • Orifice plate - Type “K” 2000 Edition formed HNBR seal on a 316 SS retainer ring
  • Dual Ring HNBR O-rings standard on a 316 SS retainer ring assembly
  • Teflon Snap Seal two-piece virgin Teflon assembly
Line Bore I.D. Tolerance...................................In conformance with AGA-3 and ISO-5167 Latest Edition
Eccentricity Repeatability...................................In conformance with AGA-3 and ISO-5167 Latest Edition
Tap Connections...................................
  • Two 1/2” NPT per side standard, two 1/2” NPT additional per side optional (TT)
  • 2” and 3” fitting sizes center bored to .375” inside diameter
  • 4” and larger sizes center bored to .500” inside diameter
  • Tolerance +/- 1/64”
Orifice Plate Seal Gap...................................
  • 2” through 6” = 0.562”, 8” through 14” = 0.688”, 16” through 20” = 0.813”
  • 24” through 30” = 0.875
Operating Shaft Location...................................
  • Dual operation standard all sizes and pressure ratings
Operating Temperature...................................Standard at -20° to 100° F, optional -40° to 1200° F
Operating Position...................................Vertical or horizontal
Reporting

An AGA 2000 Inspection report is included with the purchase of every fitting. The documented test include:

  • I.D. Bore Tolerance
  • Tap Communication
  • Orifice Eccentricity
  • Instrument Tap Diameter
  • Plate Seal Test
  • Bore Inside Diameter
  • Instrument Tap Location
  • Seal Protrusion
  • Bore Roughness
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