ASAHI/AMERICA Valves

The Benefits of Thermoplastics versus Metal
Thermoplastics are dielectric. They cannot easily support an electric charge and are immune to corrosion in the conventional sense.
Thermoplastics stay smoother than metal. The smooth surfaces of thermoplastics are unfavorable to the proliferation of microorganisms.
Thermoplastics last longer than metal. Asahi/America valves are designed to last for many years even when in contact with most corrosive liquids.
Thermoplastics do not contaminate the fluids they transport. Rouging and associated metal contamination problems are nonexistent. Thermoplastics have higher system purity than metals.
Thermoplastics have higher chemical resistance properties than most metals.
Thermoplastics have a more effective resistance to corrosion than metal. As a result of this, thermoplastics pipes and valves are used in many industries, including semi-conductor, mining, pulp and paper, electroplating, printing, landfills, aquaculture, waste water treatment, aquariums, theme parks and cruise ships. Government Regulations, notably those from the Environmental Protection Agency (EPA) favor thermoplastics’ corrosion resistance properties.
Total material and installation costs of thermoplastics are lower than with conventional metal systems.
Thermoplastics are more efficient than metals. There are numerous operational efficiencies associated with thermoplastics over metals. Advantages include chemical inertness, resistance to permeation and impurity absorption, abrasion and freeze resistance. Plus, borescoping and passivation are not required with thermoplastics.
There have been more significant advances in the field of thermoplastics, than metals in recent years. Advances in thermoplastics have made possible the needed strength and heat/pressure tolerance for the vast majority of fluid flow applications.
Thermoplastics install more easily than metals. Characteristics including lightness in weight, good maneuverability, and compact size contribute to the ease of installation.
The advantages of using thermoplastics are constantly being discovered. Lack of knowledge about the benefits of using thermoplastics is one of the main reasons for slower penetration into various industries. Asahi/America is actively trying to educate end users to upgrade to thermoplastic systems.

PVC (POLYVINYL CHLORIDE) Type 1 Cell Class 12454-A
Asahi/America uses an unplasticized PVC polymer in all its PVC valves. PVC has widespread appeal due to its dependability, availability and relatively low cost. This material has excellent chemical resistance, strength, rigidity, and modulus of elasticity and can be joined by cementing, threading or flanging. PVC has much lower thermal conductivity than metals and often does not have to be insulated. It resists attack by most acids and strong alkalis, as well as gasoline, kerosene, aliphatic alcohols and hydrocarbons, and salt solutions. Aromatic chlorinated organic compounds, lacquer solvents, esters or polar solvents such as ketones do affect PVC chemical properties. Its low cost and overall balance of properties make PVC the material best suited to the widest number of corrosive applications. Excellent for industrial chemical and plating systems, deionized water, irrigation and drainage systems. Temperature range from –30º F to 140º F.

PTFE – Teflon® (POLYTETRAFLUOROETHYLENE)
This widely used fluorocarbon is nearly insoluble and chemically inert. Teflon, in application on bearing surfaces, exhibits a natural lubricity that makes lubrication completely unnecessary and has an inherent low coefficient of friction. Its high bond strength enhances its chemical resistance properties. Teflon’s nonstick surface and nonpermeability also contributes to its wide variety of uses. It has high thermal stability, is nonflammable, and exhibits a very low dielectric constant. Its maximum temperature limit is 250º F.

PVDF (POLYVINYLIDENE FLUORIDE) Type II
This high molecular weight fluorocarbon has superior abrasion resistance, chemical properties, and mechanical strength. It maintains these characteristics over a temperature range of -40º F to 250º F. PVDF is the strongest and heaviest of the thermoplastics, and possesses dielectric properties. It is unaffected by ultraviolet exposure, and does not support the growth of fungi. Excellent for high-purity applications. PVDF can be joined by thermo-seal fusion, threading or flanging. PVDF is the only thermoplastic resistant to wet or dry chlorine, bromine and other halogens. It is highly resistant to most strong acids and bases, aliphatics, aromatics, alcohols, and chlorinated solvents, but is not recommended for ketones or esters.

CPVC (CHLORINATED POLYVINYL CHLORIDE) Type 4 Cell Class 23567-A
The chemical resistance properties of CPVC and its advantages are very similar to those of PVC; however it maintains a superior working temperature range is higher (195º F) than that of PVC, due to its increased chlorine content. Fiberglass is often added for reinforcement to increase its mechanical strength, stiffness and dimensional stability. PP material can be joined by cementing, threading or flanging. It is not recommended for use with chlorinated or aromatic hydrocarbons, esters or polar solvents such as ketones. It is suitable for hot corrosive liquids, hot or cold water systems and inorganic chemicals outside the temperature limits of PVC. It should be specified in some instances where hot corrosive liquids are being handled that an extra margin of safety is required.

PP (POLYPROPYLENE) Type 1 Cell Class PP0210867272
A member of the polyolefin family, PP is one of the lightest plastics known. It is highly crystalline; thus it is strong and hard. It possesses excellent chemical resistance (yet is less chemically resistant than PVC) to many acids, alkalis, and organic solvents. PP is not recommended for use with aromatics, strong oxidizing acids, halogens or halogenated hydrocarbons. PP can be degraded by UV exposure, so outdoor applications should include UV stabilizers. PP can be joined by thermo-seal fusion, threading or flanging. It is well suited for caustic solutions and is useful for sulfur-bearing materials, salt water, crude oil and low-pressure gas systems. Its upper temperature limit is 195º F.

PE (POLYETHYLENE)
A thermoplastic composed of the polymers of ethylene.

FRP (FIBERGLASS REINFORCED PLASTIC)
A general term relating to the reinforcement of plastic with fibrous glass. Typically, this extends the operating temperature of the material to approximately 250º F and the tensile strength (in psi) to approximately ten times that of PVC.

EPDM (ETHYLENE PROPYLENE DIMONOMER)
This terpolymer elastomer (which is made from ethylene-propylene diene monomer) is particularly well suited for seats, seals and O-rings in all thermoplastic valves. It can stand up to a variety of bases, alcohols, and oxidizing chemicals. It is recommended for water, chlorinated water, dilute acids, alkalines and ozone, but is not recommended for petroleum oils or strong acids. Because it has a negligible absorption rate, it is not susceptible to swelling. Its maximum temperature limit is 212º F.

FKM (VITON®)
A fluoroelastomer, which is used as seating and sealing material in many Asahi/America valves. It resists a wide range of chemicals, including mineral acids, salts, and aromatic hydrocarbons. Its maximum temperature limit is above 300º F.

NBR (NITRILE) (BUNA–N)
Nitrile rubber is a copolymer of butadiene and acrylonitrile. In addition to its excellent elastomeric properties, it is resistant to oil, caustics, and aliphatic hydrocarbons. Nitrile is not suitable for solvents and chlorinated hydrocarbons. Its maximum temperature limit is 212º F.

CSM (HYPALON®)
This is the DuPont name for its elastomer of chlorosulfonated polyethylene used for valve seats and seals. It resists oxidizing chemicals, concentrated acids and caustics, oils, weather, sun, and abrasion. Its maximum temperature limit is 212º F.

CR (NEOPRENE®)
A chlorinated synthetic rubber used primarily as a seating and sealing material in Asahi/America valves. It has excellent resistance to oil and weather. Additionally, it resists ozone, vegetable and mineral oils, dilute acids and caustics. Its maximum temperature limit is 212º F.

Ball Valves
Ball valves perform a quarter turn on/off or modulating function. A flow-controlling ball located within the body of the valve contains a hole through its center along one axis, which connects the inlet and outlet ports of the body. The ball itself is held in place by, and rotates 90º within, PTFE seats. These provide permanent lubrication and keep the valve 'bubble-tight.' They are backed by elastomeric cushions, which provide pressure against the ball and at the same time compensate for wear. Elastomer O-rings are used for stem and carrier seals to prevent leakage to the atmosphere. In the open position, the flow is straight through with minimal pressure drop as long as the porting through the ball is the same size as the inside diameter of the pipe.

Butterfly Valves
The name of this valve comes from the wing-like action of the flow-controlling disc, which operates at right angles to the flow. The disc has about the same diameter as the connecting pipe, and the flow is straight through, with a low pressure drop. Maintenance is easy due to the small number of moving parts. The butterfly valve can be used either as an on/off or modulating type of valve. Asahi/America has recently developed the advanced Type 56 valve, which has no metal to media or environment contact whatsoever. These valves may be operated manually, electrically, or pneumatically.

Diaphragm Valves
Diaphragm valves offer many combinations of body materials and elastomeric diaphragm materials. The valve design is abrasion-resistant and non-clogging. When the diaphragm, which is connected to the stem of the valve by a compressor, is pulled away from the bottom of the valve body or weir, the path of the fluid has a smooth, streamlined flow. Slurries at low pressure that would normally clog most other valve designs easily pass through a diaphragm valve. The valve has a top-entry design, allowing in-line maintenance; it is suitable for throttling and on/off service in applications ranging from water treatment to chemical abrasion processes. Diaphragm valves are operated manually, electrically, or pneumatically.

Check Valves
Check valves are used to prevent the reversal of flow in a line. When open and under flow pressure, the checking mechanism will move freely in the media, offering very little resistance and minimal pressure drop. We offer two basic types of check valves: swing check valves and ball check valves. A swing check valve utilizes a swinging disc, which requires only minimal back pressure to close the valve. This valve can also be modified, with a lever and weight or spring, to assist in seating faster to eliminate shock. The Asahi/America ball check valve employs a free moving ball, which unseats to permit flow in one direction, but seals against a seat to prevent backflow. Both types of valves may be installed vertically or horizontally.

Globe Valves
The flow through a globe valve follows a course that takes nearly two 90º changes in direction. But, because the seating of a globe valve is parallel to the line of flow of the liquid, it can be used to throttle the flow to any required degree or to give positive shut-offs. The economy and dependability of the Asahi/America globe valve make it desirable for many applications where this pressure drop is not critical. These valves are designed for manual operation only.

Gate Valves
The gate valve is the most widely used on/off valve for large diameter, full port applications. When the valve is fully open, it allows straight passage through an opening that is essentially the same size as the inside diameter of the connecting pipe, so there is little pressure drop through a gate valve. The valve operates when the hand wheel and stem screw (or electric actuator) move a cylindrical plug, the gate, up and down at right angles to the fluid flow. Traditionally, gate valves are used only for on/off service, but Asahi/America's unique sliding plug design provides a larger seating area than conventional gate valves, so it can be used for throttling.

Pressure Relief Valves
The thermoplastic pressure relief valve protects equipment and systems against overpressures or sudden pressure surges. Able to handle highly corrosive or ultra pure liquids, it prevents pumps from dead-heading due to unexpected shut-offs downstream (also known as a 'bypass relief valve'). It maintains back pressure in closed-loop systems to make pumps run more smoothly (also known as a back pressure valve.)

Constant Flow Valves
Using the constant flow valve provides an accurate way of controlling flow without automation (neither electricity nor an air supply is required). Accurate control is achieved by the globe style body and seat-and-plug configuration. This unique design allows the valve to maintain a constant preset flow, even if the differential pressure changes. The all thermoplastic construction makes it ideal for semiconductor, chemical, swimming pool, and salt water applications.

Sight Glass Gauge Valves
The sight glass/gauge valve is the most convenient way to visually monitor the liquid level in tanks. Its thermoplastic construction produces excellent corrosion resistance, and its compact design permits it to be safely located close to the tank.

Sediment Strainers
Sediment strainers protect pipeline components such as pumps and meters by removing suspended solids and impurities. Transparent thermoplastic construction permits easy detection of the screen's condition.

Gaskets
Asahi valve gaskets offer a unique double convex ring design that gives optimum sealing with only 1/3 the torque commonly required with flat faced gaskets.