Monoflange valves

Product Description

Block, Block & Bleed & Double Block & Bleed Monoflange Valves. Alphex Engineers manufactures precision-engineered Monoflange Valves designed for compact installation, reduced leak paths, and reliable isolation in critical Oil &Gas, Petrochemical, Chemical, Offshore, and Process industry applications. These valves integrate multiple valve functions into a single compact body, significantly reducing installation space, weight, tubing connections, and potential leak points compared to conventional multi-valve hook-up systems. Monoflange Valves from Alphex Engineers are designed for direct mounting to pressure transmitters, gauges, switches, manifolds, and process pipelines in both onshore and offshore applications.

Valve Configurations

Block Valve
- Single isolation valve arrangement
- Compact process isolation solution
- Suitable for pressure gauge and instrumentation applications
Block & Bleed valve
- One isolation valve with integrated bleed/vent valve
- Allows process isolation and safe venting during maintenance and calibration
- Reduced fittings and leak paths compared to traditional installations
Double Block & Bleed (DBB) Valve
- Two independent isolation valves with integrated bleed valve
- Positive double isolation for critical applications
- Compact single-body construction replacing multiple valve assemblies
- Enhanced operational safety and maintenance reliability
- Suitable for high-pressure and critical service applications

Needle Valve Constructions

Anti-Tamper Needle Design
- Prevents unauthorized operation
- Enhanced operational safety for critical instrument applications
- Suitable for vent and bleed services.
Bolted Bonnet Design
- Metal-to-metal body to bonnet sealing arrangement
- Superior sealing integrity for high pressure and temperature services
- Enhanced mechanical strength and pressure boundary reliability
- Recommended for critical and severe service applications.
Threaded Bonnet Design
- Compact and economical construction
- Reliable sealing arrangement for standard process applications
- Reduced maintenance and easy installation.
OS & Y (Outside Screw & Yoke) Design
- External stem threads isolated from process media
- Prevents thread contamination, corrosion, and galling
- Improved operational life and smooth valve operation.

Needle Tip Design Options

Rotating Tip Design
- Conventional needle arrangement where the tip rotates during operation
- Suitable for general isolation and throttling applications
- Cost-effective and compact design
- Reliable shut-off performance for standard services.
Non-Rotating Tip Design
- Needle tip remains stationary while stem rotates independently
- Minimizes seat galling and frictional wear
- Improves sealing performance and seat life
- Recommended for high-pressure, high-cycle, and critical applications
- Provides smooth operation and repeatable bubble-tight shut-off
- Alphex Engineers offers both rotating and non-rotating needle tip designs depending on operating pressure, media compatibility, temperature, and service conditions.

Design & Construction Features

One-piece Forged Body Construction
Barstock Construction
Compact Lightweight Design
Reduced Leak Paths
Bubble Tight Shut-off
Blow-out Proof Stem
Non-Rotating Hardened Needle Tip
Live Loaded Packing Arrangement
Fire Safe Design
Low Emission Packing Design
Anti-static Design (where applicable)
Locking Arrangement
Vent & Drain Arrangement
Extended Bonnet for Cryogenic Service
Metal-to-Metal Seat & Bonnet Sealing
Bi-directional Isolation Capability
Heat Code Traceability
NACE MR0175 Compliance for Sour Service
Suitable for Vertical & Horizontal Mounting

End Connections

Inlet Connections
RF Flanged
RTJ Flanged
API RTJ Connections
Outlet / Vent Connections
NPT
BSPT
BSPP
Socket Weld (Optional)

Packing Options

PTFE
Graphite / Grafoil
PEEK
PCTFE

Suitable for low-temperature, high-temperature, corrosive, and critical service applications.

Operation Options

T-Bar Handle
Handwheel Operated
Lockable Handle Arrangement

Material of Construction (MOC)

Forged Body Materials
- ASTM A105
- ASTM A350 LF2
- ASTM A182 F304 / F304L
- ASTM A182 F316 / F316L
- ASTM A182 F51 / F53 / F55 (Duplex & Super Duplex)
Cast Body Materials
- ASTM A216 WCB / WCC
- ASTM A351 CF8 / CF8M
- ASTM A995 4A / 5A / 6A
Exotic Materials
- Monel 400
- Hastelloy C276
- Inconel 625 / 718
- Incoloy
- Titanium
- Zirconium
- 6Mo Stainless Steel
- Nickel Aluminium Bronze (C95800)
Trim Materials
- SS316
- Duplex / Super Duplex
- Monel
- Hastelloy
- Inconel
- Tungsten Carbide Coated Trim

Design Standards & Testing

Designed and manufactured in accordance with:
- ASME B16.34
- ASME B31.3
- ASME B16.5
- API 6D
- API 598
Optional Compliance :
- API 607
- NACE MR0175.