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.

A vacuum pumping and/or abatement system for evacuating and/or abating fluid from an entity, the system comprising: a first module comprising a vacuum pumping apparatus for pumping the fluid from the entity and/or an abatement apparatus for abating the fluid evacuated from the entity; and a second module arranged adjacent to the first module in a first system dimension; wherein the first and second modules each have a maximum size in the first system dimension that is a respective integer multiple of a common fixed system value.

A coupling device for coupling flanges of two pipes includes a chain assembly and a positioning mechanism. The chain assembly includes plural connecting pieces pivotally connected one by one by pivot members. The connecting pieces at two opposite ends of the chain assembly are defined as a first connecting piece and a second connecting piece. A first pivot member is arranged at the free end of the first connecting piece, and a second pivot member is arranged at the free end of the second connecting piece. The positioning mechanism includes a first portion and a second portion pivotally connected. The first portion is pivotally connected to the first pivot member or the first connecting piece, and the second portion is detachably positioned to the second pivot member. The first portion is rotatable between a release position and a fixed position relative to the second portion.

A coupling device for coupling flanges of two pipes includes a chain assembly and a positioning mechanism. The chain assembly includes plural connecting pieces pivotally connected one by one by pivot members. The connecting pieces at two opposite ends of the chain assembly are defined as a first connecting piece and a second connecting piece. A first pivot member is arranged at the free end of the first connecting piece, and a second pivot member is arranged at the free end of the second connecting piece. The positioning mechanism includes a first portion and a second portion pivotally connected. The first portion is pivotally connected to the first pivot member or the first connecting piece, and the second portion is detachably positioned to the second pivot member. The first portion is rotatable between a release position and a fixed position relative to the second portion.

A ratchet clamp with automatic fail safe preferably includes a first clamp half, a second clamp half, a ratchet arm and a locking ratchet device. The first and second clamp halves include a substantially semi-circular shape and a V-shaped cross section. One end of the first clamp half is pivotal secured to one end of the second clamp half. The ratchet arm includes a plurality of teeth. The locking ratchet device includes a ratchet lever and a lock pawl. The ratchet arm extends from an opposing end of the first clamp half. The locking ratchet device extends from an opposing end of the second clamp half. The ratchet arm is inserted into the locking ratchet device. The ratchet lever is lifted to tighten the clamp around flanges of two pipes. The lock pawl is used to lock a position of the ratchet arm relative to the locking ratchet device.

A ratchet clamp with automatic fail safe preferably includes a first clamp half, a second clamp half, a ratchet arm and a locking ratchet device. The first and second clamp halves include a substantially semi-circular shape and a V-shaped cross section. One end of the first clamp half is pivotal secured to one end of the second clamp half. The ratchet arm includes a plurality of teeth. The locking ratchet device includes a ratchet lever and a lock pawl. The ratchet arm extends from an opposing end of the first clamp half. The locking ratchet device extends from an opposing end of the second clamp half. The ratchet arm is inserted into the locking ratchet device. The ratchet lever is lifted to tighten the clamp around flanges of two pipes. The lock pawl is used to lock a position of the ratchet arm relative to the locking ratchet device.

A V-band clamp includes first and second clamp sections each having an arcuate shape with a first end, a second end, and inside surface defining a recessed channel. A hinge pivotably connects the second end of the first clamp section to the first end of the second clamp section. At least one fastener is configured to releasably connect the first end of the first clamp section to the second end of the second clamp section in a closed position. When the V-band clamp is in the closed position, each fastener extends through an opening in an end face on the first end of the first clamp section and into a bore in an end face on the second end of the second clamp section.

A collar for connecting ducting components is provided. The collar includes a tubular wall having a line end and a free end, an annular flange extending radially outwardly from the line end, and a plurality of retaining tabs extending outwardly from the free end. A plurality of locking members are provided at the line end. The locking members are configured to releasably secure the flange to an adjacent member.

A collar for connecting ducting components is provided. The collar includes a tubular wall having a line end and a free end, an annular flange extending radially outwardly from the line end, and a plurality of retaining tabs extending outwardly from the free end. A plurality of locking members are provided at the line end. The locking members are configured to releasably secure the flange to an adjacent member.

A non-metallic fluid coupling is disclosed with electrical current transferring elements incorporated therein. The coupling is formed of two C-shaped halves of non-metal, non-conducting material, where each halve includes integral hinges and latches, or hinges and latches made of a common material with the C-shaped halves. A non-metallic, substantially rigid sealing sleeve can be incorporated into the coupling to seal the coupling while maintaining the strength of the coupling.