Walworth Valve Bodies, Bonnets, Wedges, and Discs

	Specifications ASTM
Group 1. "Carbon Steel" Class
Carbon Steel	A216, Grade WCB
Group 2. "Special Steel Class"
Carbon Steel for Low Temperatures	A352, Grade LCB
1-1/4% Chromium - 1/2% Molybdenum Steel	A217, Grade WC6
Group 3. "Special Steel" Class
5% Chromium - 1/2% Molybdenum Steel	A217, Grade C5
3-1/2% Nickel Steel for Low Temperatures	A352, Grade LC3
Group 4. "Special Steel" Class
21/4% Chromium -1% Molybdenum Steel NOTE: For extremely high temperatures and or unusually corrosive conditions, Special steels can be furnished.	A217, Grade WC9

 

Walworth Trim-Faces, Seat Rings, of Wedges, and Discs

		Specifications
	Class	AISI	ASTM
"Standard Trim"
(1) Stainless Steel 13% Chromium in combination with Cobalt Base Hard Facing	UT	–	–
(2) Stainless Steel, 13% Chromium	AA	–	A276 Type 410
(3) Nickel-Copper Alloy in combination with 13% Chromium Stainless Steel	AAA	–	–
"Special Trim"
(1) Stainless Steel, 18% Chromium, 8% Nickel, with Molybdenum	18-8SMo	Type 316	A182, Grade F316
(2) Nickel Copper Alloy or Monel	A	–	–
(3) Bronze	H	–	–
"HF" Trim (Stellite)
HF: Cobalt-Chromium- Tungsten Alloy	HF	–	–
Half HF: Cobalt-Chromium- Tungsten Alloy with 13% Chromium Stainless Steel	1/2 HF	–	–

 

Walworth Stem Material

		Specifications
	Notes	AISI	ASTM
Stainless Steel,13% Chromium	1	Type 410	A276 Type 410
Stainless Steel, 18% Chromium 8% Nickel, with Molybdenum	2	–	A276 Type 316, Con. B
Bronze	3	–	B584, Alloy C86400 B21, Alloy C46400
Nickel-Copper Alloy	4	–	–

Note 1 - Regular for all Class AA. AAA, UT, and HF Valves. Note 2 - Regular for Class 18-8SMo Valves.
Note 3 - Regular for Class H Valves. Note 4 - Regular for Class A Valves.

 

Walworth Bonnet Bolting Material

		Specifications
	Notes	ASTM
Studs
Chromium Molybdenum Steel	5	A 193, Grade 87
Chromium Molybdenum Vanadium Steel	6	A193,Grade 816
Chromium Molybdenum Steel	7	A320, Grade L7
Nuts
Carbon Steel	8	A194, Grade 2H
Carbon Steel	9	A 194, Grade 4

Note 5-Preferably used for temperatures not over 1000F. Note 6-For temperatures up to 1100F. Note 7 -For sub-zero temperatures below minus 20F to minus 150F. Note 8-For use with A193, Grades B7 and B16 studs. Note 9-For use with A320, Grade L7 studs.

Service Guides

The pressure-temperature ratings given on pages CS32 to CS34 correspond with ratings published in Amer. Natl. Std. 816.34 The ferritic steels, other than those listed for low temperature service, should not be used for temperatures below minus 20F. Pressure temperature ratings for Class 150 valves, are included on pages CS32, 33 and 34. For temperatures above approximately 6000 F, it is suggested the engineering department of Walworth Company be consulted on Class 150 valves or else that higher pressure classes of valves be used. The latter valves have marked advantages in design for higher temperatures. Many variables in pipeline fluids, including concentration, temperature, contaminants, solid materials, and velocity, affect the suitability of valve materials. Statements herein are given as general guides and are based on laboratory tests and service experience. Due, however, to the aforementioned variables, these guides are not hereby guaranteed, either expressly or implied, for particular installations. For corrosive or out-of-the-ordinary services where more precise data are needed, the Sales or Engineering Departments of Walworth Company should be consulted.

Guides for Trim Materials

The class of trim normally identifies the materials of stems and seating surfaces. In using these guides, consideration should also be given to the materials of bodies, bonnets, etc. Additionally, consideration should be given to the stem material for the more corrosive and low temperature services.

Class AA valve trim having seating surfaces of 13% chromium stainless steel: oil service up to 1100F.

Class AAA valve trim having seating surfaces of nickel-copper alloy in combination with 13% chromium stainless steel: air, steam, and water services up to 750F, and oil service up to 500F.

Class UT (Universal) valve trim having seating surfaces of cobalt-chromium-tungsten alloy in combination with 13% chromium stainless steel: all general services normally using AA or AAA times, namely oil, air, steam, and water.

Class HF valve trim having hard faced seating surfaces of cobalt-chromium-tungsten alloy: high temperature and most other services for which steel valves may be used. For some service conditions other hard facings may be applied,

Class 18-8SMo valve trim having seating surfaces of Type 316 stainless steel: wide applications in the sulfite pulp industry, processing of acetic and phosphoric acids and their derivatives, and low temperatures service.

Class H valve trim having bronze seating surfaces: fresh water, air, lubricating oil, and steam up to 450F, and those low temperature services where bronze is satisfactory.

Class A valve trim having seating surfaces of nickel-copper alloy: wide applications in handling alkalies, sea water, brine, organic substances, non-oxidizing solutions, and many air-free acids.

Steam Service

For steam service, Gate, Globe, and Angle Valves in Class 150 and Class 300, will be furnished with Class AAA or Class UT trims unless Class HF is ordered. In higher pressure valves Class HF trim is recommended regardless of temperature. Swing check valves in all pressures will be furnished with Class AA trim for all services unless Class HF or Special trim is ordered.

Miscellaneous Parts

Yokes, yoke nuts, bonnet bushings, gland plates, handwheels, and miscellaneous parts are made of carefully selected materials which many years of experience have demonstrated to be best suited to the requirements of such parts. Note: Walworth Company reserves the right to change designs, materials, and specifications without notice.