Every engineering field has its list of abbreviations to help convey information quickly and easily. Here is such list of abbreviations related to piping engineering. Hope it will be useful to new entrants as well as professionals alike.

Sr.	Abbreviation	Description
1	ANSI	American National Standards Institute Inc
2	API	American Petrolium Institute
3	ASA	American Standards Association
4	Asb	Asbestos (Gaskets)
5	ASME	The American Society of Mechanical Engineers
6	ASTM	The American Society for Testing and Materials
7	AWWA	American Water Works Association
8	BBE	Bevel both ends
9	Bbl	Barrel
10	Bdr	Bleed ring
11	BE	Beveled end
12	Bfy	Butterfy (valve)
13	Bld	Blind (flange)
14	Bld	Spectacle blind (blate between flanges)
15	BLE	Bevel large end
16	Blk	Black (pipe)
17	BOE	Bevel one end
18	BOM	Bill of materials
19	BOP	Bottom of pipe
20	Brz	Bronze (valve)
21	BSE	Bevel small end
22	BW	Buttweld

Sr.	Abbreviation	Description
23	Chk	Check (valve)
24	CI	Cast iron
25	Cm	Centimeter
26	Conc	Concentric
27	Cpl	Coupling
28	CS	Cast steel, carbon steel, cap screw
29	CSC	Car seal closed
30	Csg	Casing
31	CSO	Car seal open
32	Csw	Concentric swage
33	Cu	Cubic
34	CW	Chain wheel
35	CWO	Chain wheel operator
36	CWP	Cold water pressure
37	D&T	Drill and tap
38	D&W	Doped and wrapped (pipe)
39	DES	Double extra strong
40	DI	Ductile iron
41	Dia	Diameter
42	Dim	Dimension
43	Ditto	Do not use this term
44	DSAW	Double sub-merged arc welded (pipe)
45	Dwg #	Drawing number

Sr.	Abbreviation	Description
46	Ea.	Each
47	Ecc	Eccentric
48	El	Elevation (on drawing)
49	Elec	Electrical
50	Ell	Elbow
51	Eol	Elbolet
52	ERW	Electric resistance weld (pipe)
53	Esw	Eccentric swage
54	EUE	External upset ends
55	Ex.hvy	Extra heavy
56	Ex.stg	Extra strong
57	Exp jt	Expansion joint
58	F&D	Faced and drilled (flanged)
59	F/F	Face of flange
60	FAB	Fabricate/fabricator
61	FAS	Free along side
62	FE	Flanged ends / flow element
63	Fem	Female (ends)
64	FF	Flat/full face
65	Fig	Figure (number)
66	Flex	Flexitallic (gasket brand name)
67	Flg.	Flange
68	Flgd	Flanged ends / flow element
69	FOB	Free on board
70	FS	Forged steel
71	FSD	Flat side down
72	FSU	Flat side up
73	Ft	Feet/foot
74	FW	Field weld/fire water

Sr.	Abbreviation	Description
75	Gal	Gallon
76	Galv	Galvanised
77	GG	Gauge glass
78	GJ	Ground joint (union)
79	Glb	Globe (valve)
80	GR	Grade
81	Gsk	Gasket
82	HC	Hose coupling
83	Hdr	Header
84	Hex	Size-sided head, bolt, plug etc.
85	HN	Heat number
86	Hvy	Heavy
87	IBBM	Iron body bronze mounted(valve)
88	ID	Inside diamter
89	ID	Inside diamter
90	Insi	Insulation
91	IPS	Iron pipe size
92	IS&Y	Inside screw & yoke (valve)
93	ISO	Isometric (drawing)
94	IUE	Internal upset ends
95	Jkscr	Jack screw
96	Jt (s)	Jt. (joints)
97	JW	Jacket water

Sr.	Abbreviation	Description
98	Lati	Lateral
99	Lb (s). #	Pound (s) # symbol for pounds
100	Lg	Length, long, level gauge
101	Lin Ft	Liner feet
102	LJ	Lap joint (flange)
103	LLC	Liquid level controller
104	LOL	Latrolet
105	LP	Line pipe
106	LR	Long radius
107	M	Meter/one thousand
108	M&F	Male and female (ends)
109	MAT’L	Materials
110	Max	Maximum (a warehouse stocking level)
111	MFD	Mechanical flow diagram
112	Mfg	Manufacturer
113	MI	Malleable iron
114	Min	Minimum (a warehouse stocking level)
115	Misc	Miscellaneous (schedules of pipe)
116	Mk	Mark (spool piece)
117	MM	Millimeter
118	MRR	Materials receiving report
119	MSS	Manufacturers Standards Society of the Valve and Fittings Industry
120	MTO	Material take-off (from drawings)
121	NC	Normally closed
122	Nip	Nipple (pipe)
123	No or #	Number
124	NPS	Nominal pipe size
125	NPT	Nominal pipe thread
126	NU	Non-upset (ends)

Sr.	Abbreviation	Description
127	OD	Outside diamter
128	Orf	Orifice
129	OS&D	Over short and damage (report)
130	OS&Y	Outside screw and yoke (valve)
131	Oz	Ounce
132	P&ID	Piping and instrumentation diagram
133	PBE	Plain both ends
134	Pc	Piece (mark for spool pieces)
135	Pdl	Paddle (a blind plate between flanges)
136	PE	Plain ends
137	PI	Pressure indicator (valves & gauge assembly)
138	PLE	Plain large end
139	Plt	Plat (steel)
140	PO #	Purchase order or number
141	POE	Plain one end
142	Pr	Pair of items
143	Press	Pressure
144	PS	Pipe support
145	PSE	Plain small end
146	psi	Pounds per square inch
147	psig	Pounts-force suqre inch, guage
148	PSV	Pressure safety (relief) valve
149	PVC	Poly vinyl chloride
150	PVF	Pipe, valves and fittings

Sr.	Abbreviation	Description
151	PW	Potable wter
152	Qty	Quantity
153	Rad	Radius
154	Rdcr	Reducer
155	Rec’d	Received (materials)
156	Red	Reducer
157	Reqn	Requisition
158	REV	Revision
159	RF	Raised face
160	RPM	Revolutions per minute
161	RR	Red rubber (gasket type)
162	RS	Rising stem (valve)
163	RTE	Reducing tee
164	Rtg	Rating
165	RTJ	Ring type joint (flange facing)
166	S/40	Schedule 40 (of pipe or fittings)
167	SC	Sample connecitons
168	Sch	Schedule (of pipe or fittings)
169	Scrd	Screwed (ends)
170	Sdl	Saddle (pipe)
171	SE	Screwed ends
172	Skt Bld	Skillet blind (plate between flanges)
173	Smls	Seamless spec
174	SO	Slip-on (flange)
175	SOL	Sockolet
176	SPEC	Specification
177	Spl Sht	Spool sheet (from isometric drawing)
178	Sq	Square feet, yards etc.
179	SR	Short radius, stress relieve
180	SRL	Short radius ell
181	SS	Stainless steel
182	Std	Standard (a pipe or fitting schedule)
183	STD	Standard (a pipe or fitting schedule)
184	Stl	Steel
185	Stm	Steam
186	Sub	Short length of pipe or rod
187	SW	Socket weld
188	Swg	Swage nipple
189	SWP	Safe working pressure

Sr.	Abbreviation	Description
190	T&C	Threaded and coupled
191	T&G	Tongue and groove (flange facing)
192	Tbg	Tubing
193	Thk	Thick
194	Thr’d	Threaded
195	TI	Temperature indicator
196	TLE	Thread large end
197	TOE	Thread one end
198	TOL	Threadolet
199	TSE	Thread small end
200	TW	Thermometer well
201	Typ	Typical (repeat the same item)
202	Un	Union
203	VA	Valve
204	Vac	Vacuum
205	Vol	Volume
206	Wd	Width/wide
207	WE	Weld end
208	WI	Wrought iron
209	WN	Weld neck (flange)
210	WOL	Weldolet
211	WP	Working pressure
212	WT	Wall thickness/weight
213	XR	X-ray (at pipe welds)
214	XS	Extra strong
215	XXS	Double extra strong
216	Yd	Yard