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Working in the HVAC and Refrigeration industry there are many times when you are going to have applied torque when working on a particular job. In this blog, we help you understand the basics of torque and a method of applying torque. A bolt that has been over tightened can be just as disastrous as one that hasn't been tightened enough. A bolt that has been tightened beyond recommended torque specs can easily break in service.
Torque is measured as a unit of force acting on a rotating lever of some set length. North American made hex head cap screws have radial lines on their heads that indicate their tensile strength. When replacing a fastener, use a quality at least equal to or greater than the original fastener used on the machine. The more marks on the head, the higher the quality. Thus, bolts of the same diameter vary in strength and require a correspondingly different tightening torque or preload. Remembering that torque is the turning effort or force applied to the fastener to preload it, or place it in tension, and is normally expressed in inch-pounds (in.lb) or foot-pounds (ft.lb). A one pound weight or force applied to a lever arm one foot long exerts one foot-pound or twelve inch-pounds of torque. Note: Where possible always use OEM torque values which may differ from the table below.
All torque values are expressed in ft.lb.
Always run fasteners up snug (do not over tighten) with a regular wrench and then observe the following four steps unless OEM instructions are available.
For various HVAC and Refrigeration product information visit www.Parker.com/Sporlan.
Article contributed by Glen Steinkoenig, product manager, Contaminant Controls, Sporlan Division of Parker Hannifin.
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Today more and more applications are utilizing “heat reclaim” as a means of providing a supplementary or even a primary heat source. Heat reclaim can significantly lower energy costs. Heat reclaim is best described as the process of reclaiming heat that would normally be rejected by an outdoor condenser. Typically, the refrigerant is diverted to an air handler in an area that requires heat. One of the older applications of heat reclaim is in a supermarket since a supermarket has a constant supply of heat removed from the many refrigerated display fixtures and coolers. Today there are many cost-effective applications of heat reclaim in refrigeration, air conditioning, dehumidification, and heat pump systems.
While the most popular application of heat reclaim is air, water heating is popular in supermarkets, convenience stores, and restaurants, which all use considerable amounts of hot water. Essentially any application that requires heat can recover the heat from a refrigeration or air conditioning system. The energy efficiency of recovered heat will almost always be more efficient than any other purchased heat source. The common sense question is “Why reject heat to the outdoors when additional heat is required in any other moderate temperature application within the system or building?” 3-Way refrigerant heat reclaim valves make it convenient to recover rejected or waste heat.
Valves may be installed in either a horizontal or vertical position. However, it should not be mounted with the coil housing below the valve body.
Figures 2 & 3 show typical piping schematics for the two basic types of piping arrangements, series and parallel condensers. The selection of the piping arrangement will depend on the sizing of the reclaim coil and the control scheme of the system.
If the parallel piping arrangement is used, the reclaim condenser must be sized to handle 100% of the rejected heat at the conditions and time at which the reclaim coil is being utilized.
If the series piping arrangement is used, care and safety measures should be taken to prevent the mixing of subcooled refrigerant with hot gas vapors. These safety measures could include pressure or temperature lockout controls and time delay relays.
For both parallel and series piping, when the idle condenser is pumped down to suction pressure, a small solenoid valve can be used to pressurize the idle condenser prior to the 3-way valve shifting. This may reduce the potential for stress and fatigue failure of the refrigerant piping.
3-Way Heat Reclaim Valves with 3-way pilot valves are available in a variety of different sizes. These valves are available with an optional “bleed” port, see Figure 1. The bleed port allows the refrigerant to be removed from the heat reclaim coil or heat exchanger when it is not being used. There are two reasons why the refrigerant is removed from the heat reclaim coil. One is to maintain a proper balance of refrigerant in the system (i.e., refrigerant left in the reclaim coil could result in the remainder of the system operating short of charge). A second reason is to eliminate the potential of having condensed refrigerant in an idle coil. When an idle reclaim coil has condensed or even subcooled liquid refrigerant sitting in the tubes there is a potential for a problem. When refrigerant liquid, either saturated or subcooled, is mixed with hot gas refrigerant, the reaction of the mixing can cause severe liquid hammer. Hot gas mixed with liquid can create thousands of pounds of force and has the potential of breaking refrigerant lines and valves.
An alternate method of removing the refrigerant from a heat reclaim coil is to use a separate normally open solenoid valve and an optional fixed metering device, see Figures 2 & 3. The separate solenoid valve allows the flexibility of pumping out the reclaim heat exchanger as a liquid instead of a vapor. There are two benefits to pumping out the reclaim coil as a liquid: (1) Removal of any oil that may be present in the reclaim heat exchanger. (2) The refrigerating effect of the liquid can be used to lower the superheat of vapor entering the compressor, instead of cooling the heat reclaim heat exchanger. Sporlan recommends that recognized piping references be consulted for assistance in piping procedures. Sporlan is not responsible for system design, any damage resulting from system design, or for misapplication of its products.
Note: A check valve should be installed in the heat reclaim pump out or bleed line whenever the reclaim heat exchanger is exposed to temperatures lower than the saturated suction temperature of the system. This will prevent migration of refrigerant to the coldest location in the system.
Use optional solenoid valve and piping if pump out is required and “C” model Heat Reclaim Valve is used, see Note 4. It is optional to omit this solenoid valve and piping on systems using “B” model Heat Reclaim Valve.
Restrictor, Part #2449-004, may be required to control pump out rate on an inactive condenser.
The pilot suction line must be open to common suction whether or not Heat Reclaim Coil is installed at the time of installation and regardless of Heat Reclaim Valve model/type.
Proper support of heat reclaim valves is essential. Concentrated stresses resulting from thermal expansion or compressor vibrations can cause fatigue failure of tubing, elbows and valve fittings. Fatigue failures can also result from vapor propelled liquid slugging and condensation induced shock. The use of piping brackets close to each of the 3-Way valve fittings is recommended.
This check valve is required if lowest operating ambient temperature is lower than evaporator temperature.
Restrictor, Part #2449-004, may be required to control pump out rate on inactive condenser.
Pilot suction line must be open to common suction whether or not Heat Reclaim Coil is installed at time of installation and regardless of Heat Reclaim Valve model/type.
Proper support of heat reclaim valves is essential. Concentrated stresses resulting from thermal expansion or compressor vibrations can cause fatigue failure of tubing, elbows and valve fittings. Fatigue failures can also result from vapor propelled liquid slugging, and condensation induced shock. The use of piping brackets close to each of the 3-Way valve fittings is recommended.
For additional information on 3-Way Heat Reclaim Valves download Parker Sporlan Bulletin 30-20 or visit the product page here.
HVACR Tech Tip Article contributed by Jim Eckelkamp, senior application engineer, Sporlan Division of Parker Hannifin
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HVACR Tech Tip: How to Determine Total Refrigerant System Charge When Using Head Pressure Control
14 Nov 2018
Today more and more applications are utilizing “heat reclaim” as a means of providing a supplementary or even a primary heat source. Heat reclaim can significantly lower energy costs. Heat reclaim is best described as the process of reclaiming heat that would normally be rejected by an outdoor condenser. Typically, the refrigerant is diverted to an air handler in an area that requires heat. One of the older applications of heat reclaim is in a supermarket, since a supermarket has a constant supply of heat removed from the many refrigerated display fixtures and coolers. Today there are many cost-effective applications of heat reclaim in refrigeration, air conditioning, dehumidification and heat pump systems.
While the most popular application of heat reclaim is air, water heating is popular in supermarkets, convenience stores and restaurants, which all use considerable amounts of hot water. Essentially any application that requires heat can recover the heat from a refrigeration or air conditioning system. The energy efficiency of recovered heat will almost always be more efficient than any other purchased heat source. The common sense question is “Why reject heat to the outdoors when additional heat is required in any other moderate temperature application within the system or building?” 3-Way refrigerant heat reclaim valves make it convenient to recover rejected or waste heat.
The design and operation of Parker Sporlan Head Pressure Control Valves are discussed thoroughly in Bulletin 90-30. Installation and service is covered in Bulletin 90-31. This Climate Control blog will provide complete charging instructions, from determining the correct amount of refrigerant to actually charging the system.
If the manufacturer of your equipment provides charging information it should be used. However, if it is not provided, the following procedure is suggested.
When “refrigerant side” head pressure control is utilized on a system, one of the most important factors is determining the total system refrigerant charge. While on most packaged units the amount of charge is listed on the unit, the required charge for a field built-up system cannot be listed by the manufacturer. The charge is usually added when the system is started up until “proper” system performance is reached. However, this is not satisfactory and if the system is to function properly year-round, the correct amount of extra charge must be calculated ahead of time.
When changing refrigerants on a retrofit, be sure to calculate the refrigerant charge required for the new refrigerant. The density of the alternate refrigerants varies considerably from their CFC predecessors. In other words, if you remove 10 pounds of R-12 from a system being retrofitted to R-401A, do not charge the system with 10 pounds of R-401A. Typically, an R-401A system would only need approximately 90% of the R-12 previously required.
There are two methods of calculating the extra charge necessary to flood the condenser if the condenser manufacturer does not publish this data.
The easiest method is to calculate the volume of the condenser coil and then use the density factor of the refrigerant shown in Table 1 on Page 4 of Bulletin 90-30-1 to figure the pounds of refrigerant necessary to completely flood the condenser coil at the appropriate ambient. The factors involved in calculating the extra pounds of refrigerant are:
a. Length of tubing and return bends in condenser
b. Minimum ambient temperature at which systems will be required to function
c. Tubing size and wall thickness
The primary point to remember in selecting the proper density factor is that when the liquid drain valve (ORI, OROA, or LAC) is throttling, the refrigerant temperature will be at the same temperature as the ambient.
EXAMPLE: Calculate the extra refrigerant charge necessary for a Refrigerant 22, roof-top, air conditioning unit (40°F evaporator and a minimum condensing temperature of 90°F) with compressor unloading to 33-1/3% of full compressor capacity. To determine the equivalent length of tubing in a condenser proceed as follows: First, count the number of tubes and multiply this by their length.
Example: 150 tubes x 7.55 feet = 1132.5 feet
Next, count the return bends and multiply them by the factor shown in Table 1.
Example: 150 bends x .250 for 1/2 inch bends = 37.5 feet
Then add this 37.5 feet to the 1132.5 feet for a total of 1170 feet
The system uses a 30 hp condensing unit with a condenser coil containing 1170 equivalent feet of 1/2 inch tubing (tubes and return bends). Assume a design temperature of minus 20°F minimum ambient. From Table 1 we find the density factor necessary to calculate the pounds of extra refrigerant to completely flood the condenser at minus 20°F: 1170 feet x .102 pounds/foot = 119 pounds.
On many systems it isn’t necessary to completely flood the condenser to maintain sufficient operating head pressure (equivalent to approximately 90°F condensing temperature) because of a milder climate than Method 1 assumes. Therefore, a second method is available. The additional information found in Tables 2 and 3 on Page 8 of Bulletin 90-30-1 can be used to figure more closely the charge necessary to properly flood the condenser for sufficient head pressure at various minimum ambient temperatures. (The multipliers are applied to the extra refrigerant charge that was calculated in Method 1 to completely flood the condenser.)
EXAMPLE: Our example calls for a compressor equipped with unloaders. Since the compressor would unload at the low ambients this must be taken into consideration. This is necessary since as the compressor unloads, the condenser’s capacity increases and additional flooding is required. Using the same roof-top unit as in the earlier example (40°F evaporator and minus 20°F minimum ambient), a multiplier of .79 is shown in Table 2. And since we have unloaders (33-1/3%), this .79 is used to enter Table 3 to find a multiplier of .95. This final multiplier is applied to the 119 pounds calculated earlier to arrive at the final extra charge requirement: 119 x .95 = 113 pounds. This is added to the normal system charge to arrive at a total system charge.
Since the majority of “low and medium suction” condensing units are already flooded 75% or more for any minimum ambient temperatures below 20°F, no data is supplied for these units even when they use unloaders. The normal procedure is to recommend flooding from 90 to 100% for these units when they have unloaders.
Normally this information is supplied by the equipment manufacturer. And when it is available, it should be followed. When it is not available from the equipment manufacturer, the following suggestions are recommended.
Once the amount of extra refrigerant charge is calculated, care must be taken in charging the system to ensure the proper total amount of refrigerant getting into the system. This is especially true if the ambient temperature is below 70°F and the liquid drain valve (ORI, OROA, or LAC) is throttling the refrigerant flow from the condenser. A step-by-step procedure is given below for the two possible situations that can exist. And depending on the ambient temperature at the time the system is charged, each should be carefully followed to ensure proper system operation in both summer and winter. In either case, a liquid seal must be established in the receiver before the system can start to function correctly.
NOTE: While charging any system with head pressure control, the outdoor ambient temperature must be known. And if the system has compressor unloaders, it is important to know if they are functioning during the charging procedure. To keep this procedure as simple as possible, it is recommended that the unloaders be locked out (compressor fully loaded) during charging.
1. Connect refrigerant cylinder to a charging or gauge port on the receiver outlet valve.
2. Open the receiver valve approximately one-half way (so receiver and liquid line are connected to charging or gauge port).
3. Charge liquid refrigerant into the high side of the system. Weighing the charge is recommended with the initial charge consisting of approximately 2.5 pounds per system ton.
4. Remove the refrigerant drum and connect it to the suction side of the compressor.
5. Charge refrigerant vapor into the low side until the pressure is above atmospheric pressure. Do not admit liquid refrigerant into the low side.
6. Start the system.
7. Observe See•All moisture and liquid indicator (at receiver outlet) to see if system is properly charged for normal refrigeration cycle. CAUTION: Bubbles in the See•All can be caused by flashing due to pressure drop from pipe or accessory losses, etc.
8. If the See•All shows bubbles, more refrigerant should be added, while allowing sufficient time for the refrigerant to stabilize and clear the See•All.
9. The extra refrigerant charge for head pressure control should be weighed in now by admitting liquid refrigerant to the high side.
NOTE: When charging in ambients below 70°F the procedure is very critical. Be sure to adhere to the following steps without fail. Failure to do so will result in overcharging the system.
1. Follow instructions 1 through 7 above.
2. If the ORI, OROA, or LAC valve setting is correct for the system being charged, it is quite likely that some refrigerant will be backed up into the condenser and the See•All will indicate bubbles in the liquid line.
3. Add more refrigerant, while allowing sufficient time for the refrigerant to stabilize and clear the See•All.
4. At this point, the system is correctly charged for this type of head pressure control at the ambient temperature that exists while the charging procedure is taking place.
5. If the system is designed to operate at ambients below the ambient that exists during charging, an additional charge will have to be added now.
6. To calculate the additional charge required, follow the examples outlined under “Refrigerant Charge” except remember that the “head pressure control charge” is partially charged already. Refer to Tables 2 and 3. The difference in percentages between the minimum design ambient temperature and the ambient temperature at the time the system is charged gives the percent of extra charge still needed in the system. E.g., if this system was charged at an ambient of 50°F, we have approximately 40% of the extra charge in the system. This holds true as long as the compressor unloaders were not operating during charging. Therefore, the additional charge required is 95 minus 40 or 55% of the total extra charge calculated previously. This is .55 x 119 or 65 pounds.
Since good system performance during low ambient operation depends on proper refrigerant charge, it is very important that this phase of the installation procedure be done carefully. Many times, poor system performance will be due to too little or too much charge. And in many cases this will be the last item suspected.
HVACR Tech Tip Article contributed by Jason Forshee, application engineer, Sporlan Division of Parker Hannifin
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24 Oct 2018
When a Medium Temp rack subcools a Low Temp rack, the subcooler load will drop off during winter operation. When sizing these valves for this application, the removal of this subcooler load must be considered.
When one has compound cooling compressors or vapor injection be sure to use the subcooled temperature.
Take the total evaporator load x 110% then divide by the number of split condenser valves.
For split suction racks the total evaporator load is equal to the combined evaporator load of each suction.
For suction groups or standalone racks that are externally subcooled use the subcooled liquid temperature.
For suction groups or standalone racks that are self‐subcooled take the design condensing temperature minus 20°F.
For suction groups or standalone racks that are not subcooled take the design condensing temperature minus 20°F.
For split suction racks follow the above rules and calculate the liquid temperature for each suction group then find the weighted average liquid temperature using the formula below.
Suction 1 Evaporator Load = SQ1 Suction 1 Liquid Temperature = ST1
Suction 1 Evaporator Load = SQ2 Suction 1 Liquid Temperature = ST2
Total Evaporator load = TQ Weighted Average Liquid Temperature = WALT
[(SQ1/TQ) x ST1] + [(SQ2/TQ) x ST2] = WALT
For single suction group or standalone rack use the design suction evaporator temperature.
For split suction racks calculate the weighted average evaporator temperature using the formula below.
Suction 1 Evaporator Load = SQ1 Suction 1 Liquid Temperature = SE1
Suction 1 Evaporator Load = SQ2 Suction 1 Liquid Temperature = SE2
Total Evaporator load = TQ Weighted Average Liquid Temperature = WAET
[(SQ1/TQ) x SE1] + [(SQ2/TQ) x SE2] = WAET
The above information will provide a general guideline if no other information is available.
One psi pressure drop is required for proper operation of pilot operated solenoid valves. As a guide, try to achieve a 2 psi pressure drop during summer conditions. Where possible using a larger pressure drop will provide more of a cushion for valve operation.
For more information on Solenoid 3-Way Valves see Parker Sporlan Bulletin 30-20.
FAILURE OR IMPROPER SELECTION OR IMPROPER USE OF THE PRODUCTS DESCRIBED HEREIN OR RELATED ITEMS CAN CAUSE DEATH, PERSONAL INJURY AND PROPERTY DAMAGE.
HVACR Tech Tip Article contributed by Jim Eckelkamp, senior application engineer, Sporlan Division of Parker Hannifin
HVACR Tech Tip: Considering a Refrigeration System Retrofit? Part 1
HVACR Tech Tip: Considering a Refrigeration System Retrofit? Part 2
HVACR Tech Tip: Considering a Refrigeration System Retrofit? Part 3
10 Oct 2018
With the introduction of ZoomLock Flame-Free Refrigerant Fittings we have come across many people in the HVACR industry that have questions about using it. So here we answer the 10 most common questions about using ZoomLock.
Three different jaw configurations are available to ensure a broad range of compatibility to use with your preferred tool. Options include:
Klauke: 19 kN Crimping Tool MAP2L19
RIDGID Compact Press Tool Models: RP 240, RP 241, RP 200, RP 210, RP 100
Milwaukee: M12™ FORCE LOGIC™ Press Tool 2473-20
No. ZoomLock is different than other industry crimping technology. The jaw must align between the o-ring and outer flange. Grooves in the jaws make it easy to align. The fittings will leak if you do not crimp as stated in the ZoomLock installation instructions. Proper crimping alignment is also illustrated in the photo above.
On average you can achieve 100-150 crimps per charge depending on the size fittings being crimped. Each Klauke Tool kit comes with 2 Makita Lithium-ion 2.0 Ah 18V batteries (BL1820B) and a rapid charge charging system. To prevent any downtime, it is recommended that you have both batteries charged before going to the job site and to have one charging while the other is in use.
Use the depth gauge provided or the minimum insertion depth chart to determine the correct insertion depth. Mark the tubing with a permanent marker to indicate proper insertion depth on every tube.
No, we do not have a specific product designed to crimp over the flared tubing. However, if there is at least 2 inches of straight copper tubing after the flared end and is accessible with the jaws, we suggest that you cut the flared end off and crimp directly to the tube.
No, ZoomLock is specifically designed for copper to copper connections. Connecting to dissimilar metals can cause formicary corrosion issues that could cause a failure.
ZoomLock has been approved by UL-207, ASHRAE 15, International Code Council – Evaluation Service (ICC-ES), International Mechanical Code (IMC), Universal Mechanical Code (UMC), and International Residential Code (IRC). These approvals are all that is needed in most areas. Please contact your local building inspector with questions prior to install.
The o-ring is a highly engineered HNBR Parker o-ring that has been used in HVAC applications by OEMs and suppliers for many years with no issues.
Figure 1 below shows an example of a good tube. Figure 2 is an example of a tube with a bad scratch that requires proper tube preparation. It is very important to follow deburring, sanding and inspection steps 4 to 8 in the installation instructions.
Skipping the installation instructions will cause the tube to leak. It is very important to use the scouring pad and deburr tool included in the kit. Refrigerant gas at the maximum rated 700 psi pressure is more likely to leak than water at a much lower pressure, therefore, following the tube preparation instructions is very important. See the video below for proper tube preparation.
Download our complete list of ZoomLock Troubleshooting and Frequently Asked Questions here.
Article contributed by Parker Sporlan Division.
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