Zinc coated galvanized steel pipes are a type of steel pipe that have been coated with a layer of zinc to help prevent corrosion. The process of galvanizing involves the application of a zinc layer to a steel pipe through either hot-dip galvanization or electro-galvanization.

Hot-Dip Galvanization

In the hot-dip galvanization process, the steel pipe is dipped into a bath of molten zinc. This process allows the zinc to form a metallurgically bonded coating that is highly resistant to wear and weathering. The thickness of the zinc layer can be controlled by the duration of immersion in the bath and the thickness of the original steel.

 

Thickness	1-200mm；or as required	Length:	2000-16000mm，or as required
Dimensions	16-1020mm；(1/2inch~40inch)Dimensions	Technique	Hot Rolled Or Cold Rolle
Zinc Coating	pre galvanized steel pipe: 60-150g/m2 hot dipped galvanized steel pipe:200-460g/m2	Surface treatment	Cold galvanizing，Hot dip galvanized
Certification:	CE, ISO, SGS，BV，Mill Certificate	Standard:	ASTM，JIS，GB，DIN，EN
price terms	FOB,CRF,CIF,EXW, CPT	Payment Terms	T/T, L/C at sight,West Union
Grade	Q195—Grade B, SS330, SPC, S185
	Q215—Grade C,CS Type B, SS330, SPHC，
	Q235—Grade D, SS400, S235JR, S235JO, S235J2，
	Q345—SS500, ST52，S355JR
Delivery Detail	Standard has Stock;  Normal About 3-5days; Custom-made 15-20days；According to order’s quantity.
Packing	standard export packing (inside:water proof paper,outside:fumigated wooden box) Hexagon Shape Bundle, Covered With Tarpaulin, Containers Or In Bulk

hot-dip/cold galvanized steel pipe specification

regulation	grid	OD mm	Wall thickness mm	Minimum wall	Welded pipe ( 6 m fixed length)		Galvanized pipe ( 6 m fixed length)
Nominal inner diameter	inch			Thick mm	Meter weight kg	Root weight kg	Meter weight kg	Root weight kg
DN15	1/2	21.3	2.8	2.45	1.28	7.68	1.357	8.14
DN20	3/4	26.9	2.8	2.45	1.66	9.96	1.76	10.56
DN25	1	33.7	3.2	2.8	2.41	14.46	2.554	15.32
DN32	1.25	42.4	3.5	3.06	3.36	20.16	3.56	21.36
DN40	1.5	48.3	3.5	3.06	3.87	23.22	4.1	24.6
DN50	2	60.3	3.8	3.325	5.29	31.74	5.607	33.64
DN65	2.5	76.1	4	3.5	7.11	42.66	7.536	45.21
DN80	3	88.9	4		8.38	50.28	8.88	53.28
DN100	4	114.3	4		10.88	65.28	11.53	69.18
DN125	5	140	4.5		15.04	90.24	15.942	98.65
DN150	6	168.3	4.5		18.18	109.08	19.27	115.62
DN200	8	219.1	6 (welded pipe)		31.53	189.18
DN200	8	219.1	6.5 hot-dip galvanizing				36.12	216.72

GB / T 3091-2001 hot-dip galvanized pipe wall thickness deviation

name Weigh	Chinese standard				Enterprise standard				Contrast conclusion
	Low pressure fluid conveying welded steel pipe				Welded steel pipe
	GB/T3091-2001				Q/YF01-2002
1	Steel pipe outer diameter				Steel pipe outer diameter, outer diameter allowable deviation				Better than Chinese standards
	Outer diameter D/mm	Tube outer diameter deviation mm		Tube outer diameter Deviation mm	Outer diameter D	8″	± 0.60mm
	D< 48.3	± 0.5mm				5″-6″	± 0.50mm
	48.3<D < 168.3	± 1.0%				4″	± 0.40mm
	168.3<D < 508	± 0.75%		+2.4 -0.8		3″-“	± 0.30mm
	D>508	± 1.0%		+3.0 -0.8		2″ or less	± 0.20mm
	Wall thickness deviation	± 12.5%			Wall thickness S	1.8 5.75mm	5%
2	Usual length		Allowable deviation		length	Usual length		Allowable deviation	Better than Chinese standards
	4M-12M		+20 -0			2 inches or less		5-0
	Double length: 5-10mn ® should be left for each double in the usual length Margin		+20 -0			2.5 inches – 4 inches		5-0
						5 inches or more		15-0
						Special length		20-0

 

Electro-Galvanization

Electro-galvanization, on the other hand, uses electrical current to deposit the zinc onto the surface of the steel. This process provides a more uniform coating and allows for better control over the thickness of the zinc layer. However, electro-galvanized pipes may not be as durable as hot-dip galvanized pipes, especially in harsh environmental conditions.

Advantages of Zinc Coated Galvanized Steel Pipes

1. Corrosion Resistance: The zinc coating provides a barrier between the steel and the environment, preventing the corrosion that would otherwise occur when the steel is exposed to air and moisture.
2. Long Lifespan: Because of their corrosion resistance, galvanized steel pipes can have a long service life, often up to 50 years in rural environments and 25 years in more severe urban and coastal environments.
3. Low Maintenance: Once the galvanized steel pipes are installed, they require little maintenance because the zinc coating is very durable.
4. Toughness: The galvanization process makes the pipes more durable and tough, which can be an advantage in applications where the pipes may be exposed to mechanical damage.

Applications of Zinc Coated Galvanized Steel Pipes

Galvanized steel pipes are used in a variety of applications, including:

• Plumbing: They are often used for carrying water in both residential and commercial buildings.
• Construction: Galvanized steel pipes are used in construction for a variety of purposes, including scaffolding, fencing, and as structural elements in buildings.
• Industrial Applications: In industries, these pipes are used for transporting substances like gases, combustible fluids, and corrosive chemicals.
• Agriculture: They are used in irrigation systems, greenhouses, and other agricultural structures.

In conclusion, zinc coated galvanized steel pipes are a popular choice for many applications due to their corrosion resistance, durability, and long lifespan. However, they must be used appropriately as they are not suitable for transporting certain types of materials, like highly acidic or alkaline substances, because these can corrode the zinc layer.