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Taisei Kogyo COS-H Duplex Oil Filter for Continuous Lubrication Systems

Nichiboku's industrial Insights

Introduction

Lubrication systems supporting critical industrial machinery require continuous oil circulation, even while filter elements are being serviced.

The Taisei Kogyo COS-H Duplex Oil Filter uses two filter chambers and a changeover handle. Flow can be transferred from the operating chamber to the standby chamber, allowing the isolated element to be replaced without shutting down the complete lubrication system.


Blue duplex oil filter machine with Taisei Kogyo logo and text OIL FILTERS LIST, COS-H, TYPE DUPLEX FILTER.
Taisei Kogyo COS-H duplex oil filter featuring an aqua-blue design with dual vertical chambers, equipped with a central changeover handle for efficient oil filtration.

Continuous Duplex Filtration

The COS-H combines two welded filter housings with a central changeover mechanism. One chamber performs filtration while the other remains isolated for maintenance or standby service.

Key characteristics include:

  • Element replacement without system shutdown

  • Welded filter-case construction

  • Upward element extraction

  • Multiple element media and filtration ratings

  • Optional clogging indicator

  • Optional magnet for collecting magnetic particles

  • JIS, ANSI and JPI flange configurations

The changeover procedure must follow the manufacturer’s operating instructions to maintain oil circulation and correctly isolate the chamber being serviced.

Technical Overview: Taisei Kogyo COS-H duplex filter

Parameter

Confirmed Specification

Manufacturer

Taisei Kogyo Co., Ltd.

Product Series

COS-H

Filter Type

Duplex oil filter

Standard Fluid

Mineral oil

Maximum Working Pressure

2.0 MPa

Standard Working Temperature

−10°C to 90°C

High-Temperature Configuration

Up to 150°C, subject to element, seal and indicator restrictions

Nominal Connection Range

15A to 100A

Standard Flow-Rate Range

70 to 1,750 L/min

Standard Connection

JIS 20K SOP, flat face

Alternative Flanges

Selected JIS, ANSI and JPI ratings

Element Extraction

Upward

Allowable Element Differential Pressure

0.7 MPa

Bypass Valve

Not provided

Optional Indicator

Visual, electric-contact or micro-capacity electric-contact type

Optional Magnet

Available

The published flow-rate range is based on oil with a density of 0.86, kinematic viscosity of 32 mm²/s, 10 μm filtration and pressure drop below 0.05 MPa. Actual capacity must be verified against the operating fluid, viscosity, temperature and selected filter size.

Filter Element Selection

Available filtration media include:

  • C-fiber

  • Pleated paper

  • Wire gauze

  • Notch wire

Filtration options extend from micron-rated elements to mesh-rated configurations. Flow direction depends on the selected media:

  • C-fiber, paper and wire gauze: inside-to-outside flow

  • Notch wire: outside-to-inside flow

A replacement element must be identified using the complete COS-H element code. Taisei Kogyo uses both individual and common replacement-element codes for the same product, depending on whether the reference appears on the drawing, nameplate, voucher or tag.

Each COS-H duplex assembly contains two filter elements. The manufacturer also specifies that an SP sealing-parts set covers one filter chamber, meaning two SP sets are required when seals are replaced in the complete duplex assembly.

Blueprint-style diagram of a Taisei Kogyo duplex filter with front, rear, left, and right views labeled 0°, 90°, 180°, 270°.
Technical blueprint of the Taisei Kogyo COS-H duplex oil filter, showcasing a comprehensive 360-degree view with twin housings, flanged connection, and changeover mechanism.

Industrial Applications

The COS-H may be evaluated for continuous mineral-oil filtration in:

  • Turbine and compressor lubrication systems

  • Power-generation auxiliary equipment

  • Marine machinery lubrication systems

  • Heavy industrial equipment

  • Centralized oil-circulation systems

  • Manufacturing and process machinery

Final selection requires confirmation of flow rate, fluid type, viscosity, pressure, temperature, filtration rating, flange standard and available maintenance clearance.

Engineering Drawing and Technical Catalogue

For dimensional verification, connection arrangements and installation requirements, review the official COS-H dimensional drawing:

The official technical catalogue provides the operating specifications, model-code structure, filtration options, flow-rate information, pressure-drop data, dimensions and element sizes:

Spare Parts and Replacement Identification

Original spare-parts documentation should be reviewed when identifying replacement elements, sealing-parts sets and internal components for an existing COS-H assembly.

COS-H Spare Parts List 1:

COS-H Spare Parts List 2:

For replacement requirements, the complete filter model, element code, filtration rating, flange specification, indicator configuration and photographs of the existing nameplate should be provided.

International Sourcing from Japan

Nichiboku supports industrial end users, maintenance departments and procurement teams requiring Taisei Kogyo duplex filters, replacement elements and sealing-parts sets.

Review Taisei Kogyo filtration products through Nichiboku:

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