ダイコー List of Products and Services

Daiko Co., Ltd. will answer your questions regarding gaskets and packing. "Is it possible to reuse a gasket that has been used once?" → Reuse is not recommended regardless of the usage period or type. Although flanges may appear smooth at first glance, they have microscopic irregularities. A gasket that has been used once deforms to fit the contours of the flange. If this deformed gasket is reused, gaps may form between the flange and the gasket, leading to the possibility of leaks. *For more details, please refer to the PDF document or feel free to contact us.

Daiko Corporation will answer your questions regarding gaskets. "What could be the cause of a leak during a pressure test using a joint sheet?" → (1) The shape is F.F (full face). (2) Stress relaxation (compression of the gasket) has occurred. (1) F.F. gaskets require a greater tightening force compared to F.R. (ring type) gaskets because they have a larger contact area with the flange. A leak may have occurred due to insufficient tightening surface pressure, so we recommend changing the shape to F.R. (2) There is a possibility that the tightening force has decreased due to stress relaxation (compression of the gasket). Please retighten with the initial tightening force. *For more details, please refer to the PDF document or feel free to contact us.

Daiko Co., Ltd. will answer your questions regarding gaskets and packing. "What is the difference between SUS316 and SUS316L?" → There is a difference in workability. SUS316L is a stainless steel that is easier to process than SUS316. SUS316 contains a higher amount of hard metals (Cr, Ni), making it difficult to work with, but by lowering the carbon content, it becomes slightly softer and easier to process. (The "L" stands for low carbon.) The main difference is the carbon (C) content, with SUS316L having "0.03% or less," which falls under the "0.08% or less" of SUS316. *For more details, please refer to the PDF document or feel free to contact us.

Daiko Co., Ltd. will answer your questions regarding gaskets and packing. "What should I use if Teflon is too hard and won't stop?" → We recommend Teflon cushion or soft Teflon. The core joint sheet is soft, making it easy to conform to flanges, which improves sealing performance. Soft Teflon is pure Teflon, so it can be used in processes that are sensitive to impurities. When you actually use it, we will help you select the appropriate gasket, so please feel free to consult us. *For more details, please refer to the PDF materials or feel free to contact us.

Daiko Co., Ltd. will answer your questions regarding gaskets and packing. Products like T9010-A6 and V7030(S) allow for sealing at low surface pressure by sandwiching a soft felt material in the joint sheet to improve sealing performance. However, when used in areas exposed to rain or condensation, the felt can absorb moisture, making it unsuitable. In such cases, it is better to use joint sheets like T9010-A5 or V7030(N) along with products that only have a Teflon coating.

Daiko Corporation will answer your questions regarding gaskets and packing. 〇 Creep Phenomenon It is known that fluoropolymer-based gaskets experience significant decreases in bolt axial force due to creep relaxation characteristics. This reduction in bolt axial force raises concerns about sealing performance, and the risk of leakage accidents increases due to internal pressure loads and external forces from earthquakes, making it necessary to properly manage bolt axial force through re-tightening. 〇 Countermeasure Products We offer gaskets that improve creep resistance by mixing PTFE with special inorganic fillers that have corrosion and heat resistance, suitable for use up to 200°C. Representative products include Vulcan's V7020 and Nichias's T9007LC. They are resistant to almost all fluids except for hydrofluoric acid and strong alkalis. We have stock in sheet form and can process it to your specified dimensions.

Daiko Corporation will answer your questions regarding gaskets and packing. 〇 About RCF (Refractory Ceramic Fiber) Regulations In November 2015, the Specific Chemical Substance Hazard Prevention Regulations were amended and enforced, leading to regulations concerning the handling of RCF. The purpose is to strengthen measures to prevent health hazards for workers related to refractory ceramic fibers. The "Ordinance to Partially Amend the Enforcement Order of the Labor Safety and Health Act" (Ordinance No. 294 of 2015) was promulgated on August 12, 2015, and the "Ministry of Health, Labor and Welfare Ordinance to Partially Amend the Labor Safety and Health Regulations" (Ordinance No. 141 of 2015) was promulgated on September 17, 2015. 〇 Transition to Biodegradable Ceramic Fibers In response to the regulations, we have changed the conventional ceramic fibers to biodegradable ceramic fibers developed to have solubility even when they enter the body. In terms of performance, the only difference is between fibers that dissolve in biological water (RCF-compliant products) and those that do not dissolve (RFC non-compliant products). We guarantee that there are no products that are inferior in performance compared to existing products.

◆Issue Details 　　〇When using the joint sheet as a gasket and conducting a leak test, the leakage does not stop. ◆Possible Factors 　　〇The gasket shape is FF type → Insufficient surface pressure 　　〇No paste applied → Gas permeates 　　〇Thickness is 3.0 mm → Gas is prone to permeation, significant stress relaxation ◆Countermeasures 　　〇Change the gasket shape to ring type (inner packing) 　　〇Apply gasket paste to the flange contact surface and inner diameter end face 　　〇Reduce gasket thickness to 1.5 mm (especially for smaller sizes, below 200A)

This catalog features products from Daiko Co., Ltd., which manufactures and sells various types of gaskets and industrial products. Our company processes gaskets and packing using a variety of machines, including one of Japan's largest water jet cutting machines. We also have a wide range of items such as joint sheets, rubber, sponge, and resins. Our original brand, the non-asbestos joint sheet "D-6000," is among our well-developed products. 【Featured Products】 ■ Non-asbestos Joint Sheet D-6000 ■ Graphite Spiral Gasket D-1000 ■ Teflon Cushion Gasket D-7000 ■ SGM Soft Teflon Gasket ■ Rubber Packing, etc. *This PDF is a digest version. Please feel free to contact us if you need the full version.

At Daiko Co., Ltd., we are offering a gasket fluid compatibility chart! Are you having trouble selecting gaskets and packing? With the transition from asbestos to non-asbestos, it has become difficult to choose the right type. We have compiled a list of compatible products from various manufacturers for your reference, and we hope you find it useful for your selection process. Please note that this is a guideline, and the suitable products may vary depending on the usage conditions, so feel free to contact us for more details.

At Daiko, we conduct test processing using one of Japan's largest water jets (processing range 4000W x 5800L). Various industrial products such as gaskets and packing (non-asbestos joint sheets, rubber, sponge, and resin) can be processed. "Features of Water Jet" 1. No thermal impact... Since tools like blades and drills do not touch the material, there is no heat generation. 2. Processing range... The processing range of 4000W x 5800L is one of the largest in the country. 3. No molds required... Unlike press processing, which requires molds and dies, water jet processing uses high-pressure water, so molds are not necessary. 4. Small lots... Since molds are not required, we can accommodate small lots without incurring high costs. "Water Jet Processing is Recommended for Those Who" 1. Cannot find processing services for large-diameter materials. 2. Want to test process using new materials. 3. Are troubled by changes or discoloration due to heat generation during processing. We hope to provide information that can be of help to our customers.

"Features of Water Jet" A water jet is a water pressure cutting machine that uses high-pressure water as the cutting source. It can process various industrial products such as gaskets and packing (non-asbestos joint sheets, rubber, sponge, and resin). 1. No thermal effects... Since tools like blades and drills do not touch the material, there is no heat generation. 2. Processing range... The processing range is 4000W x 5800L, one of the largest in the country. 3. No molds required... Unlike press processing, which requires molds and dies, water jet processing does not need molds as it uses high-pressure water. 4. Small lot sizes... Since molds are not required, small lot sizes can be handled without incurring high costs. "Water jet processing is recommended for the following people" 1. Those who cannot find processing options for large-diameter products. 2. Those who want to test process using new materials. 3. Those who are troubled by changes or discoloration due to heat generation during processing. We hope to provide information that can be of help to our customers.

We are processing materials using various machines, including one of the largest water jets in Japan (processing range 4000W x 5800L). We would like you to visit our factory to see how packing and gaskets are made, the scale of our factory, and what materials can be processed. ★ We are also conducting test processing, so please feel free to contact us. We hope to provide information that can be of help to our customers.

There are various factors that can cause leaks when using gaskets, but this time I will explain about interface leaks. ◆ What is an interface leak? It is a phenomenon where internal fluid leaks through the interface between the sealing material and the opposing surface (such as a flange or shaft). ◆ Countermeasures Fill the minute gaps between the sealing material and the opposing surface with clamping force. ◆ Requirements for sealing materials - Compatibility - Resilience (to respond to pressure drop due to vibrations, thermal loads, etc. during operation, and to prevent the occurrence of minute gaps)

This catalog is a comprehensive catalog (digest version) featuring products from Daiko Co., Ltd., which manufactures and sells various types of gaskets and industrial products. Our company processes gaskets and packing using a variety of machines, including one of Japan's largest water jet cutting machines (hydro-cutting machines). We also have a wide range of items, including joint sheets, rubber, sponge, and resins. Our original brand, the non-asbestos joint sheet "D-6000," is among our well-developed products. Please utilize the fluid compatibility tables and necessary information for selecting piping and valves! 【Featured Products (Partial)】 ■ Non-asbestos joint sheet D-6000 ■ Graphite spiral wound gasket D-1000 ■ Teflon cushion gasket D7000 ■ SGM soft Teflon gasket ■ Rubber packing, etc. *This PDF is a digest version. If you need the full version, please feel free to contact us.

There are various factors that can cause leaks when using gaskets, but this time I will explain about permeation leaks. ◆ What is permeation leak? 　〇 A phenomenon where the sealing material is permeated, causing the internal fluid to leak. ◆ Countermeasures 　〇 Increase the density of the sealing material by compressing it with tightening force to fill the tiny gaps inside the sealing material. ◆ Requirements for sealing materials 　　〇 Density 　　〇 Resistance to permeation 　　〇 Applying rubber or resin-based paste materials to the inner diameter end face is also effective.

Generally, the tightening force required to seal internal fluids is indicated by Wm1 and Wm2 as specified in JIS B 8265.

This catalog is a comprehensive catalog (digest version) featuring products from Daiko Co., Ltd., which manufactures and sells various types of gaskets and industrial products. Our company processes gaskets and packing using various machines, including one of Japan's largest water jet cutting machines (hydro cutting machines). We have a wide range of items, including joint sheets, rubber, sponge, and resins. We also offer our original brand non-asbestos joint sheet "D-6000" and other products tailored to domestic manufacturers such as Nichias and Bulker. Please utilize the fluid compatibility charts and necessary information for selecting piping and valves! 【Featured Products (Partial)】 ■ Non-asbestos joint sheet D-6000 ■ Graphite spiral wound gasket D-1000 ■ Teflon cushion gasket D7000 ■ SGM soft Teflon gasket ■ Rubber packing, etc. *This PDF is a digest version. If you need the full version, please feel free to contact us.

There are several issues with joint sheets, but I will explain the most common case, which is compression failure. ◆Details of the problem 　〇Cracks occurred around the gasket, making it extremely thin. ◆Possible causes 　〇Compression failure due to excessive tightening. 　〇Excessive load applied to a part of the gasket due to lack of parallelism of the flange or deformation. 　〇Localized slippage of the joint sheet due to uneven application of paste. ◆Countermeasures 　〇Tighten without exceeding the allowable tightening surface pressure of the gasket. 　〇Problems caused by improper construction such as single-sided tightening, insufficient tightening, or excessive tightening. 　〇Correct the parallelism and deformation of the flange. 　〇When applying paste, apply it thinly and evenly.

I will explain the basics for achieving stress relaxation and stable sealing properties. ◆ What is stress relaxation? 　〇 It refers to the reduction of stress in the gasket due to the deterioration or deformation of the gasket material. A high relaxation rate makes it easier for bolts to loosen. ◆ Countermeasures 　〇 Use a thinner gasket. 　〇 Change to a material with higher heat resistance. ◆ Requirements for sealing materials 　〇 High-temperature characteristics, creep resistance, strength, etc. * The thicker the sheet, the greater the stress relaxation rate, as there are more points of structural failure (proportional to thickness and volume).

We would like to introduce a gasket that can be used for high temperature and high pressure lines. The spiral type gasket is a high-performance semi-metallic gasket designed for high temperature and high pressure applications. ■ Structure - It consists of alternating layers of a V-shaped metallic thin strip (hoop) and cushioning material (filler) wound in a spiral shape, with the start and end of the winding fixed by spot welding. - There are four types of shapes: basic form, with inner ring, with outer ring, and with both inner and outer rings, tailored to fit the gasket seat of the target flange. ■ Features - Due to its distinctive structure, it can be used at high temperatures and pressures similar to metal gaskets. - It has excellent sealing properties. - It maintains sealing performance even under severe conditions of thermal cycling from low to high temperatures. * DaiKo's product [D1000 Thin Spiral Gasket Graphite (Graphitic Material)] This is a product from our original brand. We also handle products from domestic manufacturers.

The spiral gasket is used for high pressure, which can cause the sealing part of the spiral gasket to buckle. As a countermeasure, the use of inner and outer rings is recommended. By using an inner ring, deformation of the sealing part at the inner diameter is prevented. ■Example of a problem 〇 Leakage occurred from the vortex, and when the flange was released, the gasket was deformed as shown in the photo. ■Possible factors 〇 The flange was class 900 (63K) or higher, resulting in a large tightening force. 〇 The flange size was large (26B or more), making the gasket body prone to disassembly. ■Countermeasures 〇 When using graphite or Teflon fillers, use inner and outer rings. 〇 If the diameter is large, use inner and outer rings.

I was using a rubber sheet gasket, but there was a leak. When I removed the gasket to check, a part of it was torn. ■Details of the issue 〇 The rubber sheet has a low compressive strength (14.7 N/mm²), so care must be taken not to over-tighten it. 〇 If the gasket is ring-shaped or if the flange has a flat seat (in the case of RF), there is a risk of excessive surface pressure. ■Countermeasures 〇 If the flange has a full face (FF), the gasket should also be full face. 〇 If the flange has a flat seat (RF), consider whether other gaskets, such as joint sheets, can be used. 〇 Manage torque to avoid over-tightening. 〇 Set the maximum operating pressure to 1.0 MPa as a guideline.

It is difficult to implement torque management for all flanges. Please refer to the following for an idea of the force generated by tightening. Guidelines for pulling force Generated force F - An adult pulling with just wrist strength → 50–100 N - An adult pulling with one arm strength → 100–200 N - An adult pulling with upper body strength → 200–400 N