Air separators and related methods

A method of manufacturing a gas separator comprising:

• providing a first charging tower comprising a body with an upper end and a lower end defining an interior;
• filling the first charging tower with a bed of carbon molecular sieve elements and packing the bed of carbon molecular sieve elements by shaking, vibrating, moving, imparting an impulse, or combinations thereof to the body to produce a first packed bed of carbon molecular sieve elements;
• performing at least one re-pour step to add carbon molecular sieve elements to the first packed bed of carbon molecular sieve elements to produce a first re-pour bed of carbon molecular sieve elements and packing the first re-pour bed of carbon molecular sieve elements by shaking, vibrating, moving, imparting an impulse, or combinations thereof to the body to produce a second packed bed of carbon molecular sieve elements;
• providing a second charging tower comprising a body with an upper end and a lower end and a bed of carbon molecular sieve elements;
• capping the upper end of the first charging tower and the upper end of the second charging tower with an outlet manifold having a unitarily formed body,
• wherein a first outlet port in fluid communication with the first charging tower and a second outlet port in fluid communication with the second charging tower are located in the unitarily formed body of the outlet manifold;
• and
• wherein a bypass header is attached to an exterior of the outlet manifold and connected to the first outlet port and the second outlet port.