Forged Threaded Pipe Nipple 

As a manufacturer and exporter of Forged Fittings, we have received many orders and inquires of Galvanized Nipple. How many types do you know?. Customers describe their demands with a short sentence, but have you noticed that how much information is included in the short description?

Today, we will take the latest order of “DN25 Nipple Sch80 Galvanized API-5L-B TBE 100mm Long NPT” as an example to tell you the answer.

Threaded Barrel Nipples Long Type—Nipple Type

• What is Galvanized Pipe Nipple?

For laymen, they would never have thought that galvanized nipple is a pipe fitting, but the fact is this word have been using for more than 400 years in plumbing and engineering. We can’t finger out the first usage of “nipple” in piping system, the best we can do is find out that it comes from a root meaning “bill, beak, snout” – literally “small projection.”

The basic form of nipple is a short piece of pipe with a male thread at each end for connecting two other fittings.

• Threaded Nipple

In this order, the customer requires a long type nipple.

Basic nipple form may be referred to as a “Barrel Nipple” or “Pipe Nipple”. Based on this type, many different types are evolved.

Forged Pipe Nipple includes: Stainless Steel 316 Barrel Nipple, Carbon Steel A105 Long Pipe Nipple, Galvanized Nipple, Close Nipple, Black Hexagonal Nipple (Hex Nipple), Alloy Steel Long Hex Nipple, Reducing Nipple, Screwed Swage Nipple and Hose Nipple.

I’m sure there are more forms, but this time we will focus on the long pipe nipple.

Long Pipe Nipple is a basic form nipple with more distance between the threaded ends.

• Forged Pipe Nipple TBE—End type

The threaded ends are available in different patterns and you should mention your demand in orders.

Threaded End Types:

• PBE — “Plain Both Ends”.
• TBE—”Threaded Both Ends”.
• POE- TOE –“Plain One End and Threaded One End“.

Nipple Dimension Standard

Dimension standard must be described in your orders unless your manufacturer already knows.

Dimension Standard includes: ASTM A733, BS3799, ASME B16.11, ASME B36.19, and MSS SP-95.

Generally speaking, ASME B16.11 Threaded Fittings Barrel Nipple are more commonly used in the industries, but this Threaded Galvanized Nipple is complied with ASTM A733.

What is ASTM A733?

ASTM A733 is standard specification covers welded and seamless carbon steel and austenitic stainless steel pipe nipples. The mechanical requirements stated that, Pipe Nipples shall be made from new, hydrostatic tested or NDE-tested pipe, pipe and nipples shall be threaded on both ends with NPT taper pipe threads. The standard and special lengths and sizes of nipples are presented. Galvanized Nipples ordered under this specification shall be made from pipe coated on the inside and outside by the hot dip process. Samples of nipples sufficient to determine their conformance with the requirements of this specification shall be taken at random for each lot of nipples of the same pipe size, length, and material, also, samples shall be inspected to determine their conformance with the dimensional requirements, including thread dimensions

Galvanized Nipple Dimensions

The dimension is so important that they must include in markings. For ASTM A733 Threaded Nipple, it is described as DN25, Sch80, and Length is 100mm.

• Diameter

DN25 refers to it diameter. It can be expressed in NPS (Inch) and DN.

DN25 = 1 Inch, which is a common size of threaded nipples.

Diameter range: 1/8” – 12” inch, DN6 – DN300.

• Wall Thickness

ASME B16.11 Forged Threaded Fittings are expressed in 3000LB, 6000LB, but ASTM A733 Pipe Nipple are described in schedule. Sch 80 is a middle rating in ASTM A733 specifications.

Schedule range: Sch40, Sch80, Sch160, XXS.

• Length

The length 100mm refers to the overall length with thread. Length depends on diameter.

Pipe nipple length and thread length are both specified in ASTM A733.

DN	NPS	Thread Length	Pipe Nipple Lengths
			Ⅰ	Ⅱ	Ⅲ
6	1/8	6.7	50	75	100
8	1/4	10.2	50	75	100
10	3/8	10.4	50	75	100
15	1/2	13.6	50	75	100
20	3/4	13.9	50	75	100
25	1	17.3	50	75	100
32	1 1/4	18.0	75	100	150
40	1 1/2	18.4	75	100	150
50	2	19.2	75	100	150
65	2 1/2	28.9	100	150	200
80	3	30.5	100	150	200
90	3 1/2	31.8	100	150	200
100	4	33.0	100	150	200
125	5	35.7	100	150	200
150	6	38.4	100	150	200
200	8	43.4	150	200	250
250	10	48.9	150	200	250
300	12	54.0	150	200	250

The length in above table are generally referenced ones, manufacturer can select one of the above three series under unspecified conditions.

NPT Threaded Nipple—Threaded Type

Specify NPT or R in your order.

N.P.T. Nipples or National Pipe Threaded Nipples or Fittings are standard threaded nipples used within the United States. N.P.T. nipples consist of a tapered threading which has “imperfect threads” at the end of the threading. The “imperfect threads” create your seal when connecting a male to a female N.P.T part. The seal is created by torquing the NPT  threads. When the National Pipe Thread fittings are torqued, the threads flanks compress against each other creating a successful seal.

Carbon Steel Galvanized Nipple API-5L-B—Material

It is a carbon steel comes from ANSI/API 5L Specification for Line Pipe with the application of gas, water and oil transportation. API refers to American Petroleum Institute.

API 5L has PSL-1 series and PSL-2 series, both series have grade B. The chemical composition are little different between PSL-1 and PSL-2.

Seamless API 5L-B pipe is the row material for Carbon Steel Threaded Barrel Nipple, but this pipe is also available in welded.

API-5L-B Chemical Composition, Max %

Grade B	C	Mn	P	S	Si	V	Nb	Ti
PSL-1	0.26	1.20	0.03	0.03	–	–	–	–
PSL-2	0.22	1.20	0.025	0.015	0.45	0.05	0.05	0.04

c=(Nb+V)≤0.06%

d=(Nb+V+Ti) ≤0.15%

API 5L B Mechanical Properties

Tensile Strength	Yield Strength	Elongation
415 Mpa, min	245, Mpa min	23%

Galvanized Nipple—Coating

Carbon Steel Nipples are usually with  galvanized coating like other Carbon Steel Threaded Fittings.

Galvanized Nipple should be installed according to your local building codes and can be used for residential potable water and drainage applications. This nipple can be used to repair pipe or make an extension from a fitting or existing pipe