NEW YORK - Ball valves were the most frequently seen new valves shown at the 2008 Air-Conditioning, Heating, Refrigerating Expo (AHR Expo), and terms like “dual positioning” and “bi-directional” were the most often promoted technological twists.

Here is a sampling of what was being showcased:

Parker Hannifin - Refrigerating Specialties Division (www.parker.com) featured dual-position valves designed specifically to eliminate hot gas surges that can result in blown piping. The CK-2D, CK-6D, and S4AD combine the features of a solenoid valve and check valve “combating the rapid expansion of ammonia as hot gas is introduced to the line,” according to the company.

The CK-2D and CK-6D are dual-position suction stop valves that provide evaporator equalization following a defrost cycle. The S4AD dual-position solenoid valve is used in hot gas defrost applications, said the company, and combine the soft gas valve and main hot gas solenoid into one valve.

Parker-Hannifin-Sporlan Division announced an extension of its line of electric expansion valves. The company said the SER(I)-G, SER(I)-J, and SER(I)-K have nominal capacities of 30, 60, and 90 tons respectively. The valves have brass bodies and stainless steel motor housings. All models have a removable cable design and an integral sight glass. The cable design allows installation of the valve into the piping without the possibility of cable damage, the company said.

“Due to the socket connection on the cable, field replacement of the valve can be accomplished without having to replace valve wiring,” the company said.

The C-Series TXV from Emerson Climate Technologies (www.emersonclimate.com) was designed and optimized specifically for use in HFC-410A systems. The valve features, according to the company, precise superheat to allow for enhanced compressor protection.

Automatic back flush valves for open loop cooling systems were featured by Alfa Laval (www.alflaval.com). “Back flushing is the reversal of flow for a short period of time,” the company said. “It flushes out matter that has accumulated at the plate heat exchanger inlet. A typical setting is three times a day for 30 seconds. By automatically removing the loose debris on a daily basis, the back flush valve will contribute to many years of trouble-free service.”

Tek-Air Systems (www.tek-air.com) featured AccuValve, which was described as an air control valve that allows engineers to use a low-pressure drop, low energy use, and true flow feedback. The patented valve incorporates a compression section that divided and increases air velocity for laminar airflow.

Ball valves with bidirectional applications and what was billed as “improved internal parts to guarantee zero leakage” were shown by Essen Tech Co. (www.essentech.co.kr).

They also were said to come with sight glasses that allow “minute color changing in low moisture with high temperature.”

The EloFlow stainless steel ball valve with what was called equal percentage flow was shown by Elodrive (www.elodriveusa.com). The two-piece floating ball is engineered for low torque, said the manufacturer. The bypass Cv is less than 80 percent of through flow, the company said, for equal percentage flow in the bypass mode.

Wireless communicating spring return control valve actuators were featured by Spartan Peripheral Devices (www.spartan-pd.com). The models ME8600 and ME8800 were said to be compatible with two-way and three-way zone valve bodies that the company makes. The company said the technology was available to control hot water up to 250°F and chiller water to 35°F.

Apollo Valves (www.apollovalves.com) announced that it has extended its 77C Contractor Series full-port ball valve line to include a 2 1/2-inch model that can ship with either NPT or sweat end connections.

Publication Date: 02/18/2008