German standard concealed stem soft seal gate valve

1.Product Overview

German standard Concealed stem soft seal gate valve,also named non-rising stem resilient seated gate valve,is manufactured fully compliant with German DIN industrial standards including DIN3352 F4/F5(design standard),DIN3202(face-to-face dimension)and DIN3230(pressure test).

It is an upgraded generation of conventional metal-seated gate valves,adopting fully vulcanized rubber encapsulated wedge to achieve bidirectional zero leakage.The concealed stem design keeps the valve stem entirely hidden inside the bonnet without outward extension,saving installation space and avoiding stem rust,collision damage and dirt accumulation.Widely used as full-open/full-shut cut-off equipment for clean water,sewage and neutral liquid pipelines.

2.Core Design&Structural Advantages

(1)Concealed(Non-Rising)Stem Structure

The threaded part of stainless steel stem stays sealed inside the valve body;only the upper smooth shaft rotates with handwheel,no vertical lifting during operation.

Compact overall size,ideal for narrow pipe shafts,underground buried pipelines and ceiling-mounted piping.

Effectively prevent stem corrosion,sand blockage and external mechanical impact failure.

(2)Full Soft Resilient Sealing System

Ductile iron wedge fully wrapped with food-grade EPDM/NBR rubber by integral vulcanization.Slight elastic deformation of rubber compensates machining tolerance to realize bubble-tight bi-directional sealing,zero leakage under rated pressure.

Smooth straight-through flow channel without medium retention cavity,low flow resistance,no sediment buildup inside valve body.

(3)Reliable Multi-layer Stem Sealing

Triple O-ring stem sealing set replaces traditional asbestos packing:dust wiper ring+wear-resistant bearing ring+hydraulic sealing ring.Stem seal rings can be replaced online without removing the whole valve from pipelines,greatly lowering maintenance cost and downtime.

(4)Anti-Corrosion Coating Treatment

Valve body,bonnet and wedge are coated with fusion-bonded epoxy resin internally and externally(coating thickness≥250μm).Uniform anti-rust layer isolates ductile iron from fluid,suitable for sewage,underground buried and humid outdoor environments,and meets drinking water hygiene standards EN1074/WRAS certification.

(5)Smooth Labor-Saving Operation

Brass dezincification-resistant wedge nut matches polished stainless steel stem,low friction torque,light handwheel rotation even under full pipeline pressure.Optional actuators:handwheel,square cap extension rod,gearbox,electric actuator and position indicator.

3.Key Performance Merits

Zero Leakage Sealing:Soft rubber wedge eliminates metal-to-metal friction leakage of traditional gate valves,stable sealing performance with long elastic memory.

Space-Saving Concealed Stem:No protruding stem,perfect for buried pipe,narrow valve well and building concealed piping.

Durable Anti-Corrosion:Full epoxy coating avoids internal rust and scale blockage,service life 2–3 times longer than cast iron hard-seal valves.

Easy Maintenance:Online replaceable stem O-rings without pipeline shutdown;bolted bonnet for fast internal inspection.

Environment&Sanitation Friendly:Food-contact rubber coating meets European drinking water standards,no secondary pollution for water supply systems.

Wide Compatibility:DIN standard flange and structural length match European municipal and industrial pipeline systems,interchangeable with mainstream European valve brands.

4.Typical Application Fields

Municipal water supply&drainage networks,residential community pipe networks

Building HVAC,fire protection piping,high-rise building water systems

Sewage treatment plants,environmental protection wastewater pipelines

Agricultural irrigation,landscape water circulation systems

Food processing,pharmaceutical,light textile neutral fluid conveying

Underground buried pipeline projects,tunnel and underground utility corridors