Replace multiple spaces with one/none in sql server

select replace(replace(replace(LTrim(RTrim('      6      Spaces  6      Spaces.      ')),'  ',' |'),'| ',''),
--'|','')
' |','')

select replace(
replace(
replace(
LTrim(RTrim('      6      Spaces  6      Spaces.      '))
,' ',' |')
,'| ',''),
' |',' ')

--Trim the field
--Mark double spaces
--Delete double spaces offset by 1
--Tidy up