ML Standard Thread Diaphragm Seals
ML Standard Thread Diaphragm Seals
ML Standard Thread Diaphragm Seals include MLB bolt-clamped and MLH integral welded types. Compact threaded design for small-bore oilfield & chemical pipelines, pressure up to 160MPa. Multiple corrosion-resistant diaphragm materials & thread connections.
Core Advantages
Two thread-style diaphragm-seal constructions: MLB bolt-clamped type and MLH integral welded type. Compact
threaded design for small-bore pipeline installation, with optional flush flushing port for media cleaning. Wide
pressure range up to 160MPa (23206psi). A full portfolio of corrosion-resistant diaphragm materials is available for chemical and oil-field small-pipeline monitoring
Industry Application
Small-bore oil-field wellhead pipelines, chemical instrument branch lines, high-pressure hydraulic pipelines, and
pressure monitoring for small reaction kettles; for sites requiring regular media flushing and cleaning. The MLH
welded variant is preferred for high-pressure service.
Core Differences Between Two Types
1. MLB Standard Thread Type
Structure: Internal diaphragm and support bed clamped by threads and bolts; fitted with internal PTFE / NBR
sealing gasket.
Span: 0.1-40MPa (15-5800psi)
Temperature: -40~150°C; max. 200°C for span ≤10MPa
Feature: Demountable structure; internal sealing gasket can be replaced.
2. MLH Welded Thread Type
Structure: One-piece full-welded construction with no separate internal sealing components for superior sealing
integrity.
Span: 0.1-160MPa (15-23206psi)
Temperature: -40~150°C, max. 200°C
Available Basic Information Material Options
Diaphragm: Tantalum, Hastelloy C/B, Titanium, Monel, 316L, 304L, PTFE-lined 316L, gold-plated 316L
Wetted body: 304 / 316L SS, PTFE-lined 304; custom alloy available
Internal gasket (MLB only): PTFE or NBR
Connection Specifications
Connection:
Instrument port: Factory default M20×1.5(F)
Process port: Factory default M20×1.5(M); NPT, BSPP, BSPT threads available upon request
Optional flushing port: 2-1/4" NPT(F), for on-line cleaning
Size & Compatibility
Multiple diaphragm sizes for different pressure spans. Compatible with full-series pressure gauge bodies
Selection Support
Please provide working pressure, medium composition, operating temperature, process thread specification and
whether a flushing port is required. Our engineering team will confirm MLB / MLH model, diaphragm material
and provide complete dimension drawings.