1.GENERAL
- The use of valves on chlorine gas or liquid can cause many problems. Chlorine gas and liquid are, for the most part, noncorrosive when contained in a vessel.
But, if there is leakage at the air can from hypochlorous and hydrochloric acid.
The upper portion of the gland packing, contacting suface of stem and gland packing, threaded portion of the stem, gland bolt and nut can be corroded. The purpose of the Ishida Yellow Twin valve is to prevent the leakage and resultant corrosion. - Attached chloride on the stem and other valve parts can cause seat leakage, damage of the gland packing and defective operation of the valve.
- As we know, chlorine gas is toxic and used by the military and causes environ mental pollution. Ishida designed the YELLOW TWIN PACK VALVE using long experience in the production, application, and service of valves applied to chlorine applications. Date from our Repair and Service factories in Chiba, Kashima and Tokuyama was especially useful. The valve uses materials specific for chlorine and the body is painted yellow for easy identification.
2.CONSTRUCTION AND MATERIALS
- The Yellow Twin Pack utilized a unique stuffing box design that resultants in a valve that can be used successfully in chlorine application. (For detail of construction, refer to page 4-5).
- The special type of lip-packing is used for gland packing.
- The design of both the gate and the globe valve are of the non-rising stem type.
- Seat surface and body seat surface contacting the sliding surface of the stem are specially treated to prevent corrosion.
- Body materials used for low temperature chlorine service are;
Forged Steel Valves(1 1⁄2″ and smaller):ASTM A350-LF1
Cast Steel Valves,(2" and lager):ASTM A352-LCB or JIS G5152 SCPL1
3.FEATURES
- The Yellow Twin Pack Valve prevents leakage thru the gland packing and is most suitable where prevention of environmental pollution is important.
- The life of the gland packing is several times longer because of the Twin Pack mechanism to valve repair cost is reduced greatly.
- Both gate and globe valve in the Twin Pack are designed with a non-rising stem so the possibility of gland packing damage is minimal. The valve will remain maintenance free for a longer period.
- Ishida has cooperated with the manufacturer of packing to develop a suitable chlorine resistant packing for the Yellow Twin Pack valve.
- Areas of critical parts of the valve have special surface treatment to prevent attachment of chlorine. This provides smooth opening/closing of the valve and helps prevent seat leakage.
- Ishida has many years of manufacturing and repair of general purposes valves We believe we are competent to select suitable materials for low temperature service.
Comparison Table between Yellow Twin Pack Valves & Conventional Valves
Service,Specification etc. | Yellow Twin Pack Valves | General Valves | Bellows Valves |
1.Prevention for Toxic ⁄ bad smell pollution | ○ | × | ○ |
2.Grade of maintenance-free of a gland-portion | ○ | × | ○ |
3.Facility of manufacturing of large-size valve | ○ | ○ | × |
4.Safety for corrosive fluid | ○ | × | × |
5.Safety for abnormal pressure-raise | ○ | ○ | × |
6.Superiority for fluid-resistance | ○ | ○ | × |
7.Economy of a price | ○ | ○ | × |
4.SPECIFICATIONS
- Nominal Pressure Class
JIS 10K and JIS 20K - Nominal Bore Size
3⁄8″ thru 1 1⁄2″ ..........Forged Steel
2″ thru 12″ ⁄⁄...............Cast Steel - Standard types of valve are 3 types of gate, globe
(incl. Needle valves) and angle valves - Dimension
1.Standard face-to-face dimensions are shown in the dimension table of Twin Pack Valve.
2.Standard flange types are JIS 10K, JIS 20K, And ANSI Class150# & 300#.
3.Special valves...In addition to the specifications shown, Ishida can design and manufacture valves to meet your requirements...
Please contact our Sales Department with the details of your application.