I believe I will have more questions than I will have any answers for you. What kind of traps are you using? Inverted bucket, ball and float, float and thermostatic, thermodynamic etc. etc? Are they designated for the psi you are using( low pressure )? Do they have an air lock release built into them?
When you did your checks, did you have your fans on or your kiln doors open? If you just put in some setpoints, you would not get an accurate reading. You need some way to pull the heat off of your coils to get a good "flow" of steam established to check your coils. In your steam system design, are there any Y-strainers? If so, are they being blown down frequently? What about check valves? Does your condensate side of the trap have individual check valves per trap? Are all of your traps feeding back into a single condensate return line and if so, does this go straight back to the Boiler or do you have any condensate return pumps?
The reason for the questions, is because the whole steam system, from your heat valves to how your condensate can get back to your feed water tank, is imperative to the whole operation of your coils working properly. I've seen a Y-strainer clogged on a steam header and it would not purge the condensate properly. It waterlogged the header and just fed hot water to the kiln. We checked steam traps, y-strainers, check valves and ball valves and finally found our problem outside of the kiln on the distribution header.
I've also seen the check valves ( bronze swing check ) go bad where they were not seating propely and allowed a backflow back into the trap and binding it up whenever the adjoining kiln would be under a load that shared the same condensate return line. I've seen a steam operated condensate return pump not working and waterloggiing the coils. Also have seen a steam operated condensate return pump used as a reservoir and a pump, with the incoming check valve bad creating a waterlog in the coils. Every time it went to pump, it would push the condensate back into the kilns instead of back to the Boiler.
On the other part of your question, we currently have two kilns operating with the enercon fixed orifice traps. We also use Spirax Sarco and Watson McDaniel float and thermostatic traps with the air lock releases as well. All three traps perform very well. We operate at 100 psi on six kilns, 40 psi on five kilns and 15 psi on our Predryer. We check all of our traps, roughly 70 total, about once a year either with an ultrasonic listening device or with a laser thermometer. Our daily checks of our steam traps are to watch the condensate return pumps exhaust. They are steam operated and they produce a small amount of flash steam when they exhaust their motive. When we start seeing more flash coming out of the exhaust, we will go in and check the kilns that feed into that pump. As of current, we have about four bad traps in our Predryer. We initially found that out from the condensate return pump exhaust.
I hope that this might help you in one way or another. You have a wonderful and great community of knowlege, exempting myself, in this forum with the likes of Mr. Denig, Mr. Duncan, Mr. Milota and all of the other very knowledgable contributors here. If you pick everyones brains and continue to investigate the problems you are having, you will not only find the answer to your problem, you will find you have made an impact in your organization and in this great brotherhood of Kiln Operators. Best wishes to you and when you find the answer to your problem(s), please let us all know. You might be answering some questions that we might have!