HBT diaphragm seal · Five compact process interfaces · Specialty machine connections
Button Diaphragm Seal
Compact pressure isolation for threaded-union, four-bolt-flange, and homogenizer connections.
The Haygor HBT adapts a compact button diaphragm to five process-interface styles: a 1.5-inch threaded union, two defined four-bolt flange patterns, and two sanitary homogenizer arrangements. Current selections include welded or female NPT instrument connections and 316 stainless steel or Alloy C-276 wetted materials.
- Five catalog interface types
- Up to 2-inch extension noted for Types A-C
- 316 SS or Alloy C-276 wetted selections
Compact specialty pressure isolation
What is a button diaphragm seal?
A button diaphragm seal is a compact pressure-isolation assembly designed around a specific equipment or process interface. Process pressure acts on a thin metal diaphragm, while a sealed fill fluid carries that pressure to an attached gauge, transmitter, switch, or controller without exposing the instrument to the process media.
The HBT differs from general-purpose threaded and ANSI-flanged seals because its process geometry is selected from defined union, custom four-bolt, or homogenizer arrangements. That makes the mating dimensions, bolt circle, extension, gasket, and installation details central to correct selection.
Final production geometry follows the selected HBT type, verified mating dimensions, and approved Haygor configuration.
Hydraulic pressure transfer
How the HBT seal works
The HBT combines a precisely matched process interface, a metal diaphragm, and a filled pressure-transfer path.
- 1
The interface type is matched
The threaded union, bolt pattern, flange thickness, or homogenizer geometry is verified against the mating equipment.
- 2
The seal is installed
The process-facing connection is assembled with the required mating surface, gasket, fasteners, and extension geometry.
- 3
Pressure deflects the diaphragm
The metal button diaphragm responds to process pressure while separating the process from the instrument.
- 4
Fill fluid transmits the signal
The filled system transfers pressure to the connected instrument for indication, control, switching, or transmission.
Application fit
Specialty pressure measurement where the mating geometry is already defined
The HBT is suited to pressure points that use compact threaded-union, custom four-bolt, or homogenizer-style interfaces rather than a standard male NPT or ANSI process flange. Selection should begin with the mating equipment drawing—not with the instrument connection alone.
Where the HBT can fit
- Equipment with a compatible 1.5-inch threaded union
- Legacy or OEM four-bolt process interfaces
- Compatible sanitary homogenizer measurement points
- Direct-mounted gauges, transmitters, switches, or controllers
- Remote filled systems using an approved capillary attachment
Selection conditions to verify
- Exact type, outside diameter, thickness, and bolt circle
- Mating union, flange, fasteners, and gasket arrangement
- Operating, maximum, and transient pressure
- Process media, concentration, temperature, and cleaning method
- Instrument range, fill fluid, mounting, and ambient exposure
Typical equipment contexts
Compact interfaces in demanding process equipment
- Homogenizers
- OEM skids
- Specialty machinery
- Food processing equipment
- Chemical process systems
- Legacy replacements
Current configurator envelope
HBT types, connection geometry, and rating references
These selections summarize the current HBT configurator captured from Haygor's product tool. Confirm the completed filled-system rating and dimensional compatibility before release.
1.5-inch threaded union
Up to 2-inch extension noted; 420 bar configurator reference.
3.25-inch four-bolt flange
0.75-inch thick, 2.125-inch bolt circle; 350 bar reference.
3.50-inch four-bolt flange
1-inch thick, 2.50-inch bolt circle; 420 bar reference.
Two-bolt homogenizer flange
1.125-inch-thick sanitary homogenizer style; 420 bar reference.
Homogenizer, no flange
No extension; rating is governed by the mating/flange arrangement.
Wetted alloy selections
316 stainless steel or Alloy C-276 body and diaphragm.
Connection geometry and ordering selection
Start with the mating equipment, then build the HBT assembly
Identify the exact process interface and dimensional requirements first. Then select instrument connection, extension, wetted alloy, diaphragm material, gasket, fill system, and documentation.
1.5-inch threaded union
Compact union-style process interface with an extension option noted up to 2 inches.
3.25-inch OD four-bolt flange
0.75-inch flange thickness with a 2.125-inch bolt circle and extension option noted up to 2 inches.
3.50-inch OD four-bolt flange
1-inch flange thickness with a 2.50-inch bolt circle and extension option noted up to 2 inches.
Two-bolt homogenizer flange
Sanitary homogenizer interface with a 1.125-inch-thick, two-bolt flange; consult Haygor for the complete assembly.
Homogenizer without flange
Button seal supplied without the process flange for integration with the approved mating arrangement.
| Code | Process interface | Extension note | Configurator rating reference |
|---|---|---|---|
| A | 1.5-inch threaded union | Up to 2 inches | 420 bar |
| B | Four-bolt flange, 3.25-inch OD x 0.75-inch thick, 2.125-inch bolt circle | Up to 2 inches | 350 bar |
| C | Four-bolt flange, 3.50-inch OD x 1-inch thick, 2.50-inch bolt circle | Up to 2 inches | 420 bar |
| D | Sanitary homogenizer, 1.125-inch-thick two-bolt flange | None | 420 bar; consult Haygor |
| E | Sanitary homogenizer, no flange | None | Flange / mating-system rating; consult Haygor |
| Category | Code | Selection |
|---|---|---|
| Instrument connection | W | Welded, 8 mm |
| 2 | 1/4-inch NPT | |
| 4 | 1/2-inch NPT | |
| Flange / extension material | S6 | 316 stainless steel |
| Wetted body material | S6 | 316 stainless steel |
| HC | Alloy C-276 | |
| Diaphragm material | S6 | 316 stainless steel |
| HC | Alloy C-276 | |
| Captured gasket selections | NN | None |
| AL | Aluminum |
Configuration sequence
Build the HBT model deliberately
- 1. Type
- A, B, C, D, or E interface
- 2. Instrument connection
- 8 mm weld, 1/4-inch NPT, or 1/2-inch NPT
- 3. Flange / extension
- 316 stainless; extension only where applicable
- 4. Wetted body
- 316 stainless or Alloy C-276
- 5. Diaphragm
- 316 stainless or Alloy C-276
- 6. Gasket and filled system
- Confirm type-specific sealing and attachment details
Information to confirm before release
- Existing equipment manufacturer, model, and mating drawing
- HBT type plus all outside-diameter, thickness, and bolt-circle dimensions
- Operating, maximum, and transient pressure
- Process and ambient temperature plus media composition
- Body, diaphragm, extension, and gasket compatibility
- Instrument connection, model, range, and mounting method
- Direct mount or capillary, fill fluid, orientation, and support
- Required inspection, certification, and material documentation
Compare process interfaces
Related Haygor diaphragm seals
Use the HBT for its defined compact union, four-bolt, or homogenizer geometry. Compare these alternatives when the process interface follows a more general threaded, flush, or sanitary standard.
Frequently asked questions
Button diaphragm seal FAQ
These answers summarize current HBT configurator data. Final selection requires review of the exact mating equipment, process, filled system, and installation.
Ask Haygor a technical questionWhat is a button diaphragm seal?
The Haygor HBT is a compact diaphragm-seal family built around button-style process interfaces. It isolates a pressure instrument from the process while a sealed fill fluid transfers pressure from the metal diaphragm to the attached gauge, transmitter, switch, or controller.
Which HBT mounting types are available?
The current Haygor configurator lists five types: a 1.5-inch threaded union; two four-bolt flange patterns; a sanitary homogenizer configuration with a 1.125-inch-thick two-bolt flange; and a sanitary homogenizer configuration without a flange.
What pressure ratings are shown for the HBT types?
The current configurator shows 420 bar for Type A, 350 bar for Type B, 420 bar for Type C, and 420 bar as a reference for Type D. Type E is identified by flange rating. These are configurator reference values, not a substitute for verification of the completed assembly rating, which can be limited by the mating connection, temperature, materials, instrument, fill system, and installation.
Can the HBT include an extension?
The configurator specifically notes extensions up to 2 inches for Types A, B, and C. Types D and E are shown without an extension. Confirm the exact extension length and insertion geometry with Haygor before ordering.
Which instrument connections are listed?
Current HBT selections include an 8 mm welded instrument connection, 1/4-inch NPT, and 1/2-inch NPT.
Which wetted materials are available?
The current HBT configurator lists 316 stainless steel and Alloy C-276 for the wetted body and diaphragm. The flange or extension material is listed as 316 stainless steel. Final material selection must be based on the actual process chemistry, temperature, cleaning method, and expected service life.
Which gasket selections are shown?
The captured current configurator includes no gasket and aluminum gasket selections. Gasket choice is connection-dependent, so confirm the required sealing element and mating surface for the selected HBT type.
What information should I provide for a quote?
Provide the HBT type or an existing mating drawing, bolt-circle and flange dimensions where applicable, process media and concentration, operating and maximum pressure, process and ambient temperature, instrument model and range, instrument connection, direct or remote mounting, extension length, wetted materials, gasket requirement, fill-fluid constraints, and documentation requirements.
Move from mating geometry to an HBT configuration
Configure a Button Diaphragm Seal or send the complete equipment interface to Haygor.
Use the configurator for a guided starting point, or request a quote with the equipment model or drawing, HBT type, bolt pattern, pressure, temperature, process media, materials, extension, gasket, instrument, fill system, and documentation requirements.