Strong Acid System - Valves
April 23, 2004

Introduction Plug Valves Butterfly Valves Gate Valves Globe Valves New Products

Associated Links Gaskets - Strong Acid

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Introduction

A variety of valve types and materials are used throughout the strong acid system.  The corrosive nature of sulphuric acid requires that special attention be paid to materials of construction to ensure long service life and reliable operation.

Plug Valves

Plug valves are used for isolation purposes and on/off service only.  They are available in sizes from ½” through to 18”.   Sizes larger than 8” diameter are not normally used partly due to cost and the increased flange-to-flange dimensions.  For isolation purposes, gate valves are more suitable in the larger sizes.

Manufacturer	XOMOX	XOMOX	DURCO	DURCO
Model	Tufline 067	Tufline 061	G4	T-41
Type	Sleeved	Fully Lined	Sleeved	Fully Lined
Size Range	½” to 18”	½” to 8”	½” to 18”	½” to 8”
Body Material	Ductile Iron 316 SS / A351 CF8M Alloy 20 / A351 CN7M CD4MCu	Carbon Steel or Ductile Iron	Ductile Iron 316 SS / A351 CF8M Durimet  20 / A351 CN7M CD4MCu/Durcomet 100 Durcomet 5 (High Si SS)	Ductile Iron
Plug Material	Ductile Iron 316 SS / A351 CF8M Alloy 20 / A351 CN7M CD4MCu	Stainless Steel or Ductile Iron	Ductile Iron 316 SS / A351 CF8M Durimet  20 / A351 CN7M CD4MCu/Durcomet 100 Durcomet 5 (High Si SS)	Ductile Iron
Sleeve	PTFE	N/A	PTFE	N/A
Lining	N/A	PFA or FEP	N/A	PTFE
Connection	150 lb Flanged	150 lb Flanged	150 lb Flanged	150 lb Flanged
Wrench/Lever Operator	½” to 4”	½” to 4”	½” to 4”	½” to 4”
Gear Operator	4” to 18”	4” to 8”	4” to 18”	1" to 8"

The selection of materials for the body, plug and other wetted parts will depend on the service conditions.

Butterfly Valves

Butterfly valves are used primarily for flow control and regulation.  The seat design will determine if the valve will provide positive shutoff.  A swing-thru seat design should not be used for isolation as it will not provide positive shutoff.

Manufacturer	DURCO	LEWIS	XOMOX
Model	BTV 2000	-	Tufline
Type	Fully Lined	Metallic, Swing-Thru	Metallic
Size Range	2" to 24"	4" to 24"	3" to 48"
Body Material	Ductile Iron (2" to 12") Cast Steel (14" to 24")	Lewmet	Alloy 20 (1)
Disc Material	DIPA-PFA encapsulated nickel plated ductile iron	Lewmet	Alloy 20 (1)
Lining	PTFE	N/A	N/A
Connection	Lug or Wafer	Wafer	Lug or Wafer
Wrench/Lever Operator	2" to 8"	Consult Vendor	Consult Vendor
Gear Operator	2" to 24"	Consult Vendor	Consult Vendor

(1) Other materials available, consult vendor.

The selection of materials for the body, disc and other wetted parts will depend on the service conditions.

Gate Valves

Gate valves are used isolation purposes.  They are not designed for throttling service.

Manufacturer	LEWIS
Model
Type	Double Disc
Size Range	2" to 24"
Body Material	Process Iron (A278 class 35) Lewmet
Disc Material	Lewmet
Stem	Alloy 20
Seat	Lewmet
Handwheel	Non-rising
Stem	Rising

The selection of materials for the body, disc and other wetted parts will depend on the service conditions.

Globe Valves

Globe valves are used flow control. 

Manufacturer	LEWIS
Model
Port Type	Parabolic
Size Range	1/2" to 6"
Body Material	Lewmet Alloy 20
Plug Material	Lewmet
Stem	Lewmet Alloy 20
Seat	Lewmet

The selection of materials for the body, plug and other wetted parts will depend on the service conditions.

New Products

AVT (Advanced Valve Technologies) is pleased to announce the launch of its new Sulphuric Acid Valve, able to handle an unusually wide range of sulphuric acid duties. The new ANSI150 and PN16 valves, based on a proprietary Novolac material technology, will accept duties in concentrations from 1% to 99%, working at temperatures up to 190°F (90°C). This ability to handle a wide range of concentrations in Sulphuric service is an exciting development for an industry where extremely expensive exotic alloys struggle to cover a wide range of concentrations whilst PTFE lined valves suffer problems due to liner failure and exterior attack. Furthermore, the new AVT valves typically offer a 30% to 80% cost saving over these alternative valves, and a 6 week manufacturing lead-time for project volumes - compared to 15 weeks for some alloy materials. The new Sulphuric Acid Valve joins the growing range of AVT products, already recognised for "class busting" performance in Hydrochloric Acid and other corrosive media. Advanced Valve Technologies (AVT) is the world leader in applying reinforced composite technologies to valves and related products. Their range of 20 bar (300psi) rated full port ball and double offset performance butterfly valves offer outstanding corrosion resistance, 60% weight savings over metallic valves, outstanding pressure-temperature characteristics and a compelling cost of ownership for applications in the Chemical, Offshore and Marine markets.

www.advalve.com