Dear Mr. Jeerapong,
Thank you very much for your information.
I will try to explain our condition for question number #1.
Kindly please refer to attach XLS. File.
Basically we always try to send tank together (F+H).
But sometimes order quantity between F and H tank was unbalance.
That's why to complete our order sometimes we only ship hydraulic only.
Regarding question number #2, I will discuss it with our quality also.
Soon when we have information, we will forward it to you also.
Once again thank you very much for your attention and understanding.