declare @str as varchar(100)='just_test <id = 1> some_value <id = 30> a_value <id = 5>'
declare @strXML as xml

set @str =replace(@str,' <id = ','|') 
/* get rideoff last >*/
set @str = substring(@str,1,len(@str)-1) 
/*convert to cast .That could be done also in FROM */
set @strXML=cast('<root><element>'+ replace(@str,'>','</element><element>')+'</element></root>' as XML)


select 
 SUBSTRING(t.u.value('.','varchar(100)'),1,CHARINDEX('|',t.u.value('.','varchar(100)'))-1) as [value]
,SUBSTRING(t.u.value('.','varchar(100)'),CHARINDEX('|',t.u.value('.','varchar(100)'))+1,len(t.u.value('.','varchar(100)'))-CHARINDEX('|',t.u.value('.','varchar(100)'))) as [id]
from 
	(select @strXML as strXML)  m
	cross apply strXML.nodes('root/element') as t(u)

declare @t table (value varchar(20), id varchar(5))
declare @str as varchar(100)='just_test <id = 1> some_value <id = 30> a_value <id = 5>'
declare @pos int = 1, @st int = 0, @field1 varchar(20)

set @pos = CharIndex('>', @str)
while @pos > 0 begin
	set @field1 = LTrim(SubString(@str, @st, @pos-@st))
	insert @t values (SubString(@field1,1,CharIndex(' ',@field1)-1),
			SubString(@field1,CharIndex('= ',@field1)+2,Len(@field1)))
	set @st = @pos+1
	set @pos = CharIndex('>', @str, @st)
end

Select * From @t;