DN350 Slip On Flange Order

In mid-March 2025, we once again received an inquiry from our long-standing client in Shanghai regarding stainless steel DN350 slip on flanges. Upon receiving the inquiry, we promptly responded. Trusting our capabilities, the client proceeded to place an order with our company.

Procurement Information

Flange Type: Slip On Flange

Material: SS304L

Standard: ASME B16.5

Size: DN350 (14″)

Pressure Rating: Class 150

Flange Face: RF

DN350 Slip On Flanges

A DN350 Slip On Flange is a flange type designed for easy alignment, stable weldability, and cost-effective installation in medium-pressure piping systems. Its slip-over structure allows the pipe to pass through the bore for precise positioning before welding, improving sealing reliability and reducing installation errors. DN350 SO flanges are widely used in industrial pipelines, HVAC networks, cooling water systems, and chemical transfer lines, especially where large diameters require flexible assembly.

ASME B16.5 Standard

All dimensional and tolerance requirements follow ASME B16.5 – Pipe Flanges and Flanged Fittings.This standard defines critical elements such as flange outside diameter, bolt circle diameter, raised face height, pressure-temperature limits, and wall thickness requirements. These specifications ensure global interchangeability, safety consistency, and compatibility with international piping systems. Compliance with ASME B16.5 is essential for buyers seeking verified quality, stable performance, and long-term reliability.

Class 150 Slip On Flanges Dimension

Nominal Pipe Size		A	B	C	D	F	G	H	I	J
inch	mm	mm	mm	mm	mm	mm	mm	Holes	mm	mm
1/2	21.3	88.9	22.4	11.2	15.7	30.2	35.1	4	15.7	60.45
3/4	26.7	98.6	27.7	12.7	15.7	38. 10	42.9	4	15.7	69.85
1	33.4	108	34.5	14.2	17.5	49.3	50.8	4	15.7	79.25
11/4	42.2	117.3	43.2	15.7	20.6	58.7	63.5	4	15.7	88.9
11/2	48.3	127	49.5	17.5	22.4	65	73.15	4	15.7	98.6
2	60.3	152.4	62	19.1	25.4	77.7	91.9	4	19.1	120.7
21/2	73	177.8	74.7	22.4	28.4	90.4	104.6	4	19.1	139.7
3	88.9	190.5	90.7	23.9	30.2	108	127	4	19.1	152.4
31/2	101.6	215.9	103.4	23.9	31.75	122.2	139.7	8	19.1	177.8
4	114.3	228.6	116.1	23.9	33.3	134.9	157.2	8	19.1	190.5
5	141.3	254	143.8	23.9	36.6	163.6	185.7	8	22.4	215.9
6	168.3	279.4	170.7	25.4	39.6	192	215.9	8	22.4	241.3
8	219.1	342.9	221.5	28.4	44.5	246.1	269.7	8	22.4	298.5
10	273	406.4	276.3	30.2	49.3	304.8	323.9	12	25.4	362
12	323.8	482.6	327.1	31.75	55.6	365.3	381	12	25.4	431.8
14	355.6	533.4	359.1	35.1	57.15	400.1	412.8	12	28.4	476.3
16	406.4	596.9	410.5	36.6	63.5	457.2	469.9	16	28.4	539.8
18	457.2	635	461.8	39.6	68.3	505	533.4	16	31.75	577.9
20	508	698.5	513.1	42.9	73.15	558.8	584.2	20	31.75	635
24	609.6	812.8	616	47.8	82.6	663.4	692.2	20	35.1	749.3

SS304L Material

• Carbon (C): ≤ 0.03%
• Chromium (Cr): 18.0–20.0%
• Nickel (Ni): 8.0–13.0%
• Manganese (Mn): ≤ 2.0%
• Silicon (Si): ≤ 1.0%
• Phosphorus (P): ≤ 0.045%
• Sulfur (S): ≤ 0.03%
• Nitrogen (N): ≤ 0.10%

Applications

• Water distribution and wastewater treatment
• HVAC and chilled water systems
• Marine and offshore engineering
• Chemical and petrochemical transport lines
• Structural pipeline assemblies

Installation & Usage Recommendations

• Prepare beveled pipe ends for proper welding.
• Use double-welded joints (inside and outside) to increase structural integrity.
• Match the gasket type with ASME B16.5 Raised Face specifications.
• Apply bolt torque following the star-pattern tightening sequence.
• Confirm that operating pressure & temperature follow Class 150 limits.
• For SS304L systems, avoid chloride-rich environments to reduce pitting corrosion.