A vacuum system pipe coupling includes a first coupling member defining a through passage, a second coupling member defining a through passage and a securing unit. The first coupling member has a first end portion having a first lengthways extending axis, a second end portion having a second lengthways extending axis that is laterally offset with respect to the first lengthways extending axis and a first connecting portion connecting the first and second end portions. The second coupling member has a third end portion having a third lengthways extending axis, a fourth end portion having a fourth lengthways extending axis that is laterally offset with respect to the third lengthways extending axis and a second connecting portion connecting the third and fourth end portions. The securing unit is configured to secure the first end portion to the third end portion with the first and third lengthways extending axes in alignment.