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2026-06-18

304, 304L, 316, 316L - What are the differences among them?

304, 304L, 316, and 316L are all types of austenitic stainless steel. The core differences among them lie in aspects such as chemical composition, mechanical properties, corrosion resistance, welding performance, application fields, and price. The details are as follows: I. Chemical Composition 304: Carbon content ≤ 0.08% (typical value is approximately 0.06 - 0.08%), mainly composed of 18% chromium (Cr) and 8% nickel (Ni), it is a basic austenitic stainless steel. 304L: Contains a carbon content of ≤ 0.03% (the "L" indicates low carbon), a

2026-06-18

What are the precautions for installing a swing-type check valve?

1. Pre-installation Inspection (Must be Conducted) 1. **Flow Verification** The valve body is cast with a **flow direction arrow**, which must be exactly consistent with the normal flow direction of the medium; if installed in the reverse position, the backflow function will be completely lost and the valve disc will be severely damaged by the impact.

2026-06-18

What are the differences between the nominal pressure of Chinese standard valves and that of American standard valves?

1. The code, unit, and classification rules are different. 1. **National Standards (PN System, Domestic/European Standards)** Marked with **PN**, the numbers represent the normal temperature nominal pressure, with the unit based on bar/MPa. Common grades: PN6, PN10, PN16, PN25, PN40, PN63, PN100, etc. Meaning in plain language: PN16 = At normal temperature of 20℃, the rated pressure is 1.6 MPa. The number directly corresponds to the rated pressure value. 2. **American Standard (Class pound rating, ASME system)**

2026-06-18

The role of valves in the oil and gas pipeline transportation industry

Valves play a crucial role in the oil and gas pipeline transportation industry. They are the key equipment that control fluid flow, ensure system safety, and achieve efficient operation. The following elaborates on the functions of valves in the oil and gas pipeline transportation industry from multiple aspects: 1. Flow control and regulation Precise regulation: The valve regulates the flow of oil and gas in the pipeline by changing its opening degree, meeting the requirements of different working conditions. For example, in natural gas transportation, the opening degree of the valve is adjusted according to the user's consumption to ensure stable gas supply. Multi-level control: In complex pipeline networks, valves can achieve multi-level flow distribution, optimizing resource utilization. For example,

2026-06-18

What are the types and classifications of ball valves?

The ball valve is a commonly used type of valve. It controls the flow of the medium by rotating the ball. It has the advantages of simple structure, convenient operation and good sealing performance. According to different classification criteria, ball valves can be divided into the following various types:

2026-06-18

What is the applicable temperature range for the opposed-type butterfly valve and the flanged butterfly valve?

Temperature Application Notes for Wafer & Flange Butterfly Valves Key Premise: **Connection type (wafer/flange) does not determine the maximum temperature resistance; temperature rating depends on sealing and body materials.** Flange-type valves have higher rigidity and are more suitable for long-term high-temperature and fluctuating-temperature conditions. Wafer-type valves, limited by the long bolt clamping structure, offer lower stability at high temperatures. I. Soft-Sealed Butterfly Valves