# Python 3, 139 bytes

<!-- language: lang-py -->

 n=int(input())
 for i in range(9):w=(3*' ||')[i];s=' / /\/ /\_ /\ \/\__ \/\ \/_ \/ /\/ /'[i::9]*n;s=(s,' '+s[1:-1]+' ')[i%4>1];print(w+s+w)


This one was pretty easy, just build and print at once line by line

Heres the code in ungolfed form:

<!-- language: lang-py -->

 n=int(input())
 # The list with all the knot pieces
 l= [' __ ',
 '/ \\',
 ' /\/',
 '/\/ ',
 '\ \/',
 '/\ \\',
 ' /\/',
 '/\/ ',
 '\__/']
 # The first and last columns
 w = ' || || '
 # Loop for each row
 for i in range(9):
 # Exception for the first and last character in the knot (in some rows)
 s = l[i]*n
 if i % 4 > 1:
 s = ' ' + s[1:-1] + ' '
 # Print the knot for this row
 print(w[i] + s + w[i])