Q1: What are the main products you can supply?

A: We are a professional manufacturer and supplier in China for stainless steel and carbon steel pipe fittings, including stainless steel elbows, flanges, bolts, nuts, tees, reducers, and other piping products. Our product range covers both standard and custom solutions for corrosive and high-purity applications.

Q2: What is the difference between 304 and 316 stainless steel elbows?

A: 304 stainless steel (ASTM A403 WP304) offers good general corrosion resistance and is cost-effective, making it suitable for food processing, general industrial, and indoor applications. 316 stainless steel (ASTM A403 WP316) contains molybdenum, which provides superior resistance to chlorides, pitting, and crevice corrosion. It is recommended for marine environments, chemical processing, coastal installations, and pharmaceutical applications where higher corrosion resistance is required.

Q3: What is the difference between Long Radius (LR) and Short Radius (SR) elbows?

A: Long Radius (LR) elbows have a radius of R = 1.5D (1.5 times the pipe diameter) and are the standard choice for most industrial applications. They offer lower pressure drop, reduced erosion, and smoother flow. Short Radius (SR) elbows have a radius of R = 1.0D and are used where space is limited, but they create higher pressure drop and are more prone to erosion.

Q4: Why do stainless steel elbows cost more than carbon steel elbows?

A: Stainless steel elbows are more expensive due to:

• Higher raw material cost – alloying elements like chromium, nickel, and molybdenum increase cost

• More complex manufacturing – stainless steel requires specialized forming and heat treatment processes

• Lower production volume – compared to carbon steel, stainless steel fittings have lower global production volume

• Corrosion resistance benefits – the superior corrosion resistance reduces long-term maintenance and replacement costs

The higher initial cost is typically justified by longer service life and reduced maintenance in corrosive environments.

Q5: What is your minimum order quantity (MOQ)?

A: For trial orders, our MOQ is 10 pcs per size. For bulk orders, MOQ is flexible — please contact us with your target quantity for a competitive quote. Volume discounts are available for large orders.

Q6: How long is the delivery time?

A: 7-15 days for standard sizes in stock after payment confirmation. For custom orders (non-standard sizes, special grades like Duplex, or large quantities), delivery time is typically 20-30 days, depending on specifications. We will confirm the exact timeline upon order confirmation.

Q7: How do you control quality?

A: We implement strict 3-stage quality control:

• Raw material – chemical composition verified by spectrometer per ASTM A403 / EN 10253 requirements

• Production – dimensional checks during forming, heat treatment, and beveling

• Final – dimensional inspection (angle, radius, wall thickness, end preparation) per ASME B16.9, PMI testing for grade verification, and surface inspection

A Mill Test Certificate (EN 10204 Type 3.1) is provided with every shipment, including chemical analysis and mechanical test results.

Q8: What is passivation and why is it important?

A: Passivation is a chemical process that removes free iron and surface contaminants from stainless steel, restoring and enhancing the natural corrosion-resistant oxide layer. It is important because it:

• Improves corrosion resistance, especially in aggressive environments

• Reduces the risk of rust staining and contamination

• Creates a clean, passive surface suitable for food, pharmaceutical, and sanitary applications

Passivation per ASTM A967 is available upon request and recommended for most stainless steel fittings.

Q9: What is the difference between pickling and passivation?

A: Pickling is an acid bath treatment that removes heavy scale, welding discoloration, and surface impurities. It results in a matte, uniform grey finish and is typically used to clean the surface after welding or heat treatment. Passivation is a milder chemical treatment that removes free iron and restores the oxide layer, enhancing corrosion resistance. Pickling is more aggressive, while passivation is the final step for surface protection.

Q10: Can I get samples before ordering?

A: Yes. Stock samples are free of charge – you only pay the shipping cost. Custom samples require a small production fee, which will be deducted from your first bulk order.

Q11: Do you accept OEM or custom orders?

A: Yes, we accept custom orders based on your drawings, specifications, or samples. We can also apply your logo on products and packaging. Our engineering team will review your requirements and provide a solution within 24 hours.