1 in Diaphragm Valve Bonnet

1 in Diaphragm Valve Bonnet

Description

• Component: Bonnet for a 1-inch diaphragm valve.

• Purpose: Provides a pressure-tight cover for the valve body, retaining the diaphragm, stem, and internal assembly while allowing actuator or manual stem operation through a sealed interface.

• Material: Stainless steel 316 (standard); alternatives: carbon steel (painted), Hastelloy C-276, or duplex stainless steel for corrosive environments.

• Finish: Smooth machined interior; external finish to customer specification (passivized for stainless, epoxy-coated for carbon steel).

Nominal Dimensions

• Valve size: 1 in (DN25)

• Bonnet outer diameter: typically sized to match valve body — commonly 2.0–3.0 in depending on valve design

• Bolt circle and bolt hole pattern: per OEM valve standard (usually 4–6 bolts for 1 in size)

• Height (overall): approximately 1.5–3.0 in above the valve body flange

• Stem clearance and packing chamber depth: sized to accept standard packing gland or O-ring sealing arrangement for diaphragm valves

Sealing and Fastening

• Sealing method: Elastomer diaphragm compression against seat; bonnet provides clamping and contains diaphragm. Stem-to-bonnet seal via O-ring or gland packing depending on actuator type and pressure rating.

• Gasket material (body-bonnet joint): PTFE, graphite, or elastomeric gasket matched to service temperature and media compatibility.

• Fasteners: Stainless steel studs/bolts and nuts; grade 316 or 304 for standard service, duplex or higher-alloy fasteners for corrosive applications.

Pressure & Temperature Ratings

• Pressure class: Commonly rated for ASME Class 150 or PN16 for 1 in diaphragm valves; consult OEM for specific rating.

• Temperature range: Dependent on diaphragm and gasket materials. Typical range with EPDM diaphragm: -20°C to +120°C (-4°F to 248°F). With PTFE diaphragm: -40°C to +200°C (-40°F to 392°F).

Compatibility & Application Notes

• Suitable for liquids, slurries, and gases where diaphragm isolation is required to protect the actuator and external environment from process media.

• Common industries: water treatment, chemical processing, pharmaceutical, food and beverage, and slurry handling in geotechnical construction.

• When handling abrasive slurries or solids, consider reinforced diaphragms and larger bonnet clearance to avoid premature wear.

Actuation Interfaces

• Manual: Handwheel or lever connection to stem via bonnet-mounted retainer.

• Pneumatic / Electric actuators: Bonnet designed with standardized mounting pad and coupling to accept quarter-turn or linear actuators as specified by OEM.

Inspection & Maintenance

• Routine inspection: Check bonnet fasteners for torque, inspect stem seal for leakage, and examine bonnet for corrosion or cracking.

• Diaphragm replacement: Bonnet removal required for diaphragm access. Follow OEM procedure to avoid damage to diaphragm seating surfaces.

• Spare parts recommendations: Keep at least one spare diaphragm and bonnet gasket per valve in critical service.

Manufacturing & Quality

• Manufacturing standards: Machined to tolerances per OEM drawing; material traceability and mill certificates for pressure-retaining components.

• Testing: Pressure-tested as part of valve assembly to hydrostatic or pneumatic test standard per client/OEM requirements.

Ordering Information

• Provide valve model, OEM part number, valve size (1 in), material specification, pressure class, actuator type, and any special finishes or coatings when requesting replacement bonnet.

Notes

• The bonnet is specific to the valve design; verify dimensional compatibility and OEM mounting patterns before procurement.

• For geotechnical construction applications where contamination control is critical, specify hygienic finishes or lined bonnets as required.