A valve assembly (100, 200), comprising: a seat plate (120, 220) having a top surface (121, 221) and a bottom surface (129, 229); a plurality of first valve modules (170, 270) arranged in a first level (130, 230) relative to said seat plate (120, 220) such that a first seating face (171, 271) of each of said plurality of first valve modules (170, 270) is substantially co-planar with a first plane (135, 235) that is substantially parallel to at least one of said top surface (121, 221) and said bottom surface (129, 229) of said seat plate (120, 220); wherein each of said plurality of first valve modules (170, 270) comprises a first portion (172, 272) having a first lateral width (172w, 272w) and a second portion (174, 274) having a second lateral width (174w, 274w) that is less than said first lateral width (172w, 272w), said second portion (174, 274) being positioned below said first portion (172, 272), such that at least a first part of said first portion (172, 272) of each of said plurality of first valve modules (171, 271) at a first side of said first portion (172, 272) is offset from and overhangs a corresponding first side of said second portion (174, 274); and at least one second valve module (170, 270) arranged in a second level (150, 250) relative to said seat plate (120, 220) such that a second seating face (171, 271) of said at least one second valve module (170, 270) is co-planar with a second plane (155, 255) that is substantially parallel to said first plane (135, 235), wherein said second plane (155, 255) is offset from said first plane (135, 235) by a first distance (151,251), wherein said second portion (174, 274) of at least a first one of said plurality of first valve modules (170, 270) is nested with said at least one second valve module (170, 270) such that: said first side of said second portion (174, 274) of said first one of said plurality of first valve modules (170, 270) is positioned proximate a second side of said at least one second valve module (170, 270); and said overhanging first part of said first portion (172, 272) of said first one of said plurality of first valve modules (170, 270) is positioned above at least part of said at least one second valve module (170, 270); and wherein the first and second valve modules are reed valve modules. a seat plate (120, 220) having a top surface (121, 221) and a bottom surface (129, 229); a plurality of first valve modules (170, 270) arranged in a first level (130, 230) relative to said seat plate (120, 220) such that a first seating face (171, 271) of each of said plurality of first valve modules (170, 270) is substantially co-planar with a first plane (135, 235) that is substantially parallel to at least one of said top surface (121, 221) and said bottom surface (129, 229) of said seat plate (120, 220); wherein each of said plurality of first valve modules (170, 270) comprises a first portion (172, 272) having a first lateral width (172w, 272w) and a second portion (174, 274) having a second lateral width (174w, 274w) that is less than said first lateral width (172w, 272w), said second portion (174, 274) being positioned below said first portion (172, 272), such that at least a first part of said first portion (172, 272) of each of said plurality of first valve modules (171, 271) at a first side of said first portion (172, 272) is offset from and overhangs a corresponding first side of said second portion (174, 274); and at least one second valve module (170, 270) arranged in a second level (150, 250) relative to said seat plate (120, 220) such that a second seating face (171, 271) of said at least one second valve module (170, 270) is co-planar with a second plane (155, 255) that is substantially parallel to said first plane (135, 235), wherein said second plane (155, 255) is offset from said first plane (135, 235) by a first distance (151,251), wherein said second portion (174, 274) of at least a first one of said plurality of first valve modules (170, 270) is nested with said at least one second valve module (170, 270) such that: said first side of said second portion (174, 274) of said first one of said plurality of first valve modules (170, 270) is positioned proximate a second side of said at least one second valve module (170, 270); and said overhanging first part of said first portion (172, 272) of said first one of said plurality of first valve modules (170, 270) is positioned above at least part of said at least one second valve module (170, 270); and wherein the first and second valve modules are reed valve modules.