They understand the （） of automatic sludge discharging of the purifierBut they are not good in practice.
To ensure oil purifier working in normal condition,the interval between two sludge discharging should not exceed（） hours.
The （）is used to burn oil sludge.
Which harmful consequence may be the result of lube oil sludge accumulation? （）
（）are used to digest the sewage to produce innocuous sludge in a biological sewage treatment plant.
Sludge may form in the crankcase of an air conditioning compressor as a result of （）.
Each drilling unit equipped with helicopter fuel storage tanks must have the tanks installed as far as practicable from the（）.
Which lubricating oil additive is used in diesel engines to reduce the tendency for sludge and varnish to form on the engine parts?（）
Sludge may form in the lubricating oil crankcase of a reciprocating air conditioning compressor as a result of （）.
If the overflow tank high-level alarm sounds while the fuel oil tanks are being topped off, the engineer should （）.
If you are bunkering and you close off one tank in the line of tanks being filled，the rate of flow to other open tanks on the same line will（）.
The oil sludge is burnt in the （）on board I’ll show you the ashes.
One of the reasons that causes oil flowed from sludge outlet of a self-cleaning purifier is （）
How should cargo tank hatches be protected when the ullage opening is open and the tank NOT gas free?（）.
When anaerobic bacteria convert the sewage to an inert sludge,（）
It is that reduce the BOD by converting the organic content of the sewage to a chemically and organically inert sludge（）
Before the sludge in a purifier is ejected,（）
How should cargo tank hatches be protected when the ullage opening is open and the tank not gas free?（）.
An alarm device inserted between the deaerating tank and the expansion tank can notify the on-watching crew that （）
One of the reasons that cause oil flowed from sludge outlet of a self-cleaning separator is（）
The shut off valve at the gasoline tank which can be operated from outside the tank space （）.
A centrifuge of which the bowl is arranged as the upper and lower parts separate discharges the sludge（）
The oil sludge is burnt in the ______onboard.I’ll show you the ashes.
Judging from the context, the word "think-tanks"（Para.2) probably means______.A．tanks that
