DERVOS Valve Specialist
Positive Isolation Line Blind Valves — Manual & Actuated Solutions
Manufacturer and supplier of line blind valves for absolute positive isolation — sliding, swing, and spectacle types from 1" to 60", Class 150 to 2500.
Line Blind Valve Types
Each type is purpose-built for specific isolation requirements in oil & gas, petrochemical, and steam systems.
Line Blind Valve
Positive isolation devices for pipeline maintenance, media switching, and safety-critical shutdown.
Read more →Sliding Type Line Blind Valve
Sliding (Cam-Slide) line blinds switch between open flow and solid blind plate without spreading flanges.
Read more →Swing Type Blind Valve
Rotating spectacle-plate design for quick positive isolation in industrial steam systems.
Read more →Spectacle Blind Valve
Spectacle blinds combine open bore and blind plate for visual verification of isolation status.
Read more →Featured Products
Line blind valves from DERVOS product catalog
1" - 60" Class 150 - 2500 Line Blind Valve ASME B16.34
Size: 1'' - 60'' (DN 25 to DN 1500)
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8" Class 150# Line Blind valve ASME DIN ISO Carbon Steel
Description: Standard
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ASME B16.34 10" 150LB Line Blind Valve, RF Connection, Body A105, Turbine Operation
Type: Line Blind Valve
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DN50 CL150 High Temperature Cam-Slide Line Blind Valve Stainless Steel
Description: Standard
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F11 Swing Type Blind Valve for Industrial Steam Systems | Cost-Effective Isolation
Type: Swing-Type Blind Valve
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Forged Slide Blind Valve DN400 PN40 LF2, EN12516-1/2 for Steam Service
Type: Slide Blind Valve
View details →Latest Knowledge
Technical articles about line blind valve selection, safety, and applications
How Does a Spectacle Blind Valve Differ from a Paddle Blind?
In refinery turnaround work, pipeline isolation is often treated as a routine maintenance task until operators face leakage during hot work preparation or line intervention. Choosing between a spectacle blind valve and a paddle blind is not simply a matter of installation preference. The selection a...
Read article →Line Blind Valve Installation Mistakes to Avoid
**1. Failure to Confirm Complete Depressurization Before Installation**
Read article →DVS Sliding Blind Valve Achieves Zero Leakage and Positive Isolation for South African Oil Client in Multi-Media Pipelines
**Customer Challenge: Seal Failure and Lack of Positive Isolation During Frequent Multi-Media Switching**
Read article →Why DVS Line Blind Valves?
100% Positive Isolation
Solid blind plate physically blocks media — no reliance on soft seals alone.
Online Switching
Switch open/closed under pressure without full depressurization in many designs.
Visible Position
External indicator shows open or blind position — reduces misoperation risk.
Custom Engineering
Sizes 1"–60", Class 150–2500, carbon/stainless/alloy materials, multiple actuators.
Case Study
South African Oil Client — Zero Leakage Multi-Media Pipeline
A major South African oil client deployed DVS sliding blind valves in a pipeline system switching between oil products, natural gas, and chemical solvents. Since installation, the system achieved stable zero-leakage operation with online switching under pressure.
Certifications
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