Frequency Asked Questions

This design is considered to facilitate on-site maintenance and replacement of stem seals, as well as to address cases where the valve body may be pressurized internally. When performing maintenance, it helps eliminate potential hazards by preventing accidental stem blow-out, which could cause injury to maintenance personnel who are unaware of the condition. This is an essential design feature.

Our valves are frequently used in natural gas and other flammable and explosive gases. Therefore, detecting micro-leaks in valves, which are invisible to the naked eye, is crucial. We strictly follow the ISO15848 micro-leakage standard, using helium gas for testing to ensure that any leakage is well below the allowable limit.

In petroleum and natural gas applications, due to the acidic nature of the medium, austenitic stainless steel is often used. This type of stainless steel performs well in resisting sulfur and acid corrosion. However, to ensure optimal use of austenitic stainless steel, a proper solution heat treatment process is required to achieve precipitation and toughening. Intergranular corrosion testing is the most suitable method to assess the condition of these materials. It simulates the acid and alkali conditions of the working environment through heating and observes the corrosion on the material’s surface, as well as the weight loss caused by corrosion.

Duplex steel, a new type of stainless steel combining austenitic and ferritic phases, offers high rigidity and good corrosion resistance. However, due to the combination of these two phases, it can be brittle. To improve impact resistance, it is necessary to use a precise heat treatment process. This ensures the austenitic phase’s corrosion resistance and the ferritic phase’s rigidity while minimizing brittleness. Accurate temperature control, good sealing in the furnace, and strict timing and temperature for quenching are crucial for achieving the desired impact value.

Casting defects are a persistent issue for valve and irregular part manufacturers. This involves factors such as design, mold making, shell preparation, gating design, vent hole distribution, furnace temperature control, pouring time, steel flowability, and heat treatment processes. To address these challenges, we focus on even wall thickness, proper gating angle, durable shell materials, accurate furnace temperatures, shorter pouring times to ensure good steel flow, and uniform vent hole distribution to reduce casting defects.

Our valve products are widely used in the Middle East and offshore regions, where valves come into contact with high levels of chloride ions. In these areas, duplex steel and super duplex steel are commonly used. These materials, which combine austenitic and ferritic phases, require specialized heat treatment. Iodine corrosion testing is used to verify the effectiveness of this combination, ensuring material integrity. This requires strict control over the chemical composition and heat treatment process, which directly impacts the product’s service life and reduces user maintenance costs.

Compared to onshore petroleum and natural gas facilities, offshore and marine platforms have specific limitations and challenges. Onshore installations are more flexible with larger installation dimensions, while offshore platforms are constrained by space and cost factors. For valve suppliers, this means we must consider valve and actuator size and weight limitations. We optimize our valves by reducing both size and weight, selecting materials suited for marine climates, such as duplex and super duplex steel instead of carbon steel, and minimizing the required torque to reduce actuator size. Actuators are typically installed vertically rather than horizontally, and we use marine-grade C5M coatings or immersion coatings to extend product lifespan and reduce maintenance.

In mining and metallurgy, the media involves large, hard particles with high erosive force, strong acidity or alkalinity, and a tendency to cause clogging. When selecting valves, we must account for these factors by choosing materials and designs that are resistant to abrasion, corrosion, and clogging. The valve structure, materials, and hardness must be specially designed to overcome these challenges posed by the media.