Below are the questions asked during the event, along with their respective answers.
Q: Do blind mates interchange with all other brands or manufacturers?
A: Generally, No, blind-mates (and even standard quick connect couplings) are not interchangeable with other brands/manufacturers because designs can vary from QC supplier to supplier which can make connection impossible and affect performance outcomes in unforeseen ways. However, there have been projects in the past where several QC manufacturers have come together and developed interchangeable blind-mate designs. These types of projects require extensive collaboration and testing between all parties and usually have longer periods of time dedicated to design and engineering phases.
Q: It’s not mentioned in the presentation, but after development and first manufacturing batch, is there any type of pre-testing done or required to assure quality control before going to the customer?
A: Yes, we do full testing for all products, especially prototypes, to ensure performance under different temperatures and pressures, no spillage, and functionality of the blind-mates in the application.
Q: What is the standard amount of misalignment available for these blind mate couplings? Can this be adjusted? If so, what are the resulting effects on design and cost?
A: That depends on which type of misalignment is being considered for the specific application. Often times, for example, for radial misalignment we see ± 0.5mm to ± 1mm is standard. For the less common angular and axial misalignments the values can vary, but it is important to keep in mind that all of these can be modified but this does affect engineering and design time and can add additional cost. This again touches on the fact that blind-mate designs require a good amount of collaboration on engineering and application between the engineering team and QC Supplier.
Q: Where are the couplings used in Wind Turbines? Why does the manufacturer have to use couplings?
A: Wind turbines have high powered converters and sometimes even rechargeable batteries which require modular cooling solutions to avoid damage to the components.
Q: What is the typical range of stroke to achieve full open valves in the DN5 size?
A: The total stroke is 16mm for the DN5’s from initial mating to end of the stroke. From 0 to 14mm the valves are opening until full optimal flow is achieved (at 14mm stroke). There is also an additional 2mm of stroke for extra allowance.
Q: Do you have a design feature that prevents damage if blind mates attempt to go beyond the mechanical stop?
A: The blind-mates have a built-in mechanical stoppage which will stop the blind-mates from mating any farther in application. Another concern that can arise however is with this increased force and no further mating ability, the manifold can experience some extra force that can cause deformation to the manifold.
Q: Do you assume blind-mate connections will be made at full operating design pressure?
A: Yes, that is generally assumed and tested for.
Q: How do we select the size of the quick connect?
A: Size of the quick connect depends largely on application. The most important criteria to look at are flow and pressure drop requirements as these are directly related to the inner diameter and design of the coupling. Then, of course, engineers must ensure that the size preferred physically fits into the design. If size is an issue, then the coupling selection will have to be revisited.
Q: How do you select the material of the quick connect?
A: Material of the quick connect is determined by fluid type used as well as pressure and temperatures of the system and nearby environment.
Q: What is the flow rate range of the quick connect?
A: Flow rate of the quick connect is related to the size and type of coupling selected for the application. Flow rate and pressure drop are also closely correlated and must be looked at to ensure design requirements are met.
Q: What is the operating pressure range of the quick connect?
A: There are various operating pressure ranges for quick connect couplings. Fluid or thermal control couplings often only operate in designs that require lower operating pressures so this is not usually an issue. Most of these quick connects for these applications have operating pressures from 200 to 300 PSI.
Q: Is it assumed all blind mate connectors are custom? If so can you describe the qualification program to ensure reliability?
A: Not all blind mate connectors are custom. We have a range of standard connectors that have gone through extensive testing to ensure reliability. If there is a need for custom connectors they will also go through multiple tests to ensure the product meets the quality and specifications.
Q: Is it possible for liquid spill in the middle of connection?
A: No, spill is not possible since the valves are only open when the quick connect couplings are mated together. Due to internal design, the valves close even before the coupling and nipple physically separate, eliminating the chance for spillage.
Q: Do you have any QD’s that will work with R-134a refrigerant in a two-phase state?
A: In short, yes CEJN does have Quick Connects that operate with R-134A refrigerant. The working fluid of the system will also have an effect on seal and material selection.
Q: Does the blind mate require external locking mechanism? Or is it push to lock, pull to open?
A: The blind-mate couplings do require an outside force or locking mechanism in order to keep the coupling and nipple fully mated and in place during operation.
Q: Are the QDCs compatible with 3M dielectric fluids like Novec 7000?
A: Yes, with correct choice of seals and lubrication that is compatible.
Q: Are there ever issues with water hammer impact prevention with connection that needs to be addressed in design?
A: This is generally not a problem. In these types of applications, the sudden flow rates that occur from connections and disconnections are still not enough to be a problem for the valves.
Q: Where are couplings used in solar application?
A: Solar applications also have high powered converters and sometimes even rechargeable batteries which require modular cooling solutions to avoid damage to the components.
Q: What is the general number of mating cycles for the QDC?
A: The connectors are used differently by every customer, some do more connections than others. We test our connectors for at least 5000 connections.
Q: Can particulates interfere with closure of the valves? Is there any design feature that makes the valve robust to this type of issue?
A: If the particles are large enough they can interfere with the functionality of the connector. If a system has large particles in it, a separate filter should be considered.
Q: What is the MOQ for considering custom product?
A: This depends on which product and the amount of customization that is required. As a general guideline, a minimum would be around 50.
Q: What filtration level do you require?
A: This is depending on size of coupling but generally around 100-200 µm.
Q: What is the added value that allows you to win business against competitors?
A: CEJN adds value in over 60 years of experience in the quick connect coupling sector as providers for solutions in various sectors and applications. We use a project-based approach to develop unique solutions for our customers.
Q: Do you test for fluid compatibility internally and if so can you describe the types of test you do to ensure material compatibility?
A: Yes, we do internal compatibility tests with different fluids and concentrations, sealing materials, temperatures, and materials used for the bodies of the connectors.