The 'to' is incorrect.
Interested in Language
While reading Safe Working Conditions, I came across a sentence in which one phrase seems strange to me and there is another one, whose meaning I do not understand.
Here is the sentence:
The company is to ensure that all hoses used for acetylene and oxygen are fitted with flashback arrestors and to have been pressure tested prior to use on the vessel.
Here is how I see the sentence:
The company is to ensure that all hoses used for acetylene and oxygen are fitted with "flashback arrestors" and "have been pressure tested" prior to use on the vessel.
I haven't the slightest idea what the bolded "flashback arrestors" are and I think that "have been pressure tested" is better than "to have been pressure tested".
I may be wrong.
What is your opinion on that?
A "flashback arrestor" stops any flame from going back through the hose to the tank.